From sandstone to sapphire.

157 reference entries for everyday rocks, mineral species, families and varieties—including selenite and vivianite. Research links cover all 50 states. The linked occurrence inventory is still incomplete; this is not a list of every mineral in each state.

Occurrence does not mean permission to collect. State results use linked published occurrences and reported locality materials, not supplied gem buckets. A missing entry means our evidence is incomplete—not that the mineral is absent. Broad family matches do not establish an exact variety.

157 matching entries

Sedimentary rocks

Sandstone

Cemented sand-sized grains; may show bedding. Color alone is not diagnostic.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: arenite, arkose, greywacke, flagstone

Can resemble: Quartzite or Siltstone

1 occurrence references · Arizona

Arizona: Mexican Tank community sandstone site
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Siltstone

Fine sedimentary rock with grains smaller than sand, usually not visibly gritty.

As-found / cleaned comparison not yet available for this material.

Can resemble: Shale or Sandstone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Shale

Very fine sedimentary rock that commonly splits into thin layers.

As-found / cleaned comparison not yet available for this material.

Can resemble: Slate or Siltstone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Mudstone

Fine sedimentary rock without the strong splitting typical of shale.

As-found / cleaned comparison not yet available for this material.

Can resemble: Shale or Siltstone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Limestone

Carbonate rock, sometimes containing shells, fossils or rounded ooids.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: oolitic limestone, fossiliferous limestone

Can resemble: Dolostone or Marble

1 occurrence references · California

California: Chambless Rock Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Dolostone

Rock composed mainly of dolomite; visual separation from limestone is difficult.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: dolomite rock

Can resemble: Limestone or Marble

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Chalk

Soft, fine-grained white limestone formed largely from microscopic marine remains.

As-found / cleaned comparison not yet available for this material.

Can resemble: Gypsum or Diatomite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Conglomerate

Rounded gravel-sized fragments cemented in a finer matrix.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: puddingstone

Can resemble: Breccia or Concrete

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Breccia

Angular fragments cemented together; can also form through volcanic or fault processes.

As-found / cleaned comparison not yet available for this material.

Can resemble: Conglomerate or Concrete

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Chert

Very fine silica with waxy luster and curved fractures. Flint is a commonly used name for certain cherts.

As found · in the mudCleaned · still rough
Chert / flint · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: novaculite, mozarkite, bedded chert, nodular chert

Can resemble: Jasper or Flint

2 occurrence references · Missouri

Missouri: Mark Twain National Forest — Potosi District
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Missouri: Mark Twain National Forest — Eleven Point District
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Flint

A variety of chert, often dark nodules in chalk or limestone. A photo usually cannot establish its geographic variety.

As found · in the mudCleaned · still rough
Chert / flint · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: flint ridge flint, burlington chert, keokuk chert

Can resemble: Chert or Obsidian

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Ironstone

Iron-rich sedimentary rock, often brown, red or rusty.

As-found / cleaned comparison not yet available for this material.

Can resemble: Jasper or Hematite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Coal

Organic-rich black rock; texture and luster vary with rank.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: anthracite, bituminous coal, lignite

Can resemble: Shale or Obsidian

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Sedimentary rocks

Diatomite

Lightweight, porous sedimentary rock formed from microscopic silica shells.

As-found / cleaned comparison not yet available for this material.

Can resemble: Chalk or Pumice

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Granite

Visible interlocking quartz and feldspar crystals, often with dark mica.

As-found / cleaned comparison not yet available for this material.

Can resemble: Diorite or Gneiss

1 occurrence references · Colorado

Colorado: Pike–San Isabel National Forests
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Basalt

Usually dark, fine-grained volcanic rock, sometimes containing bubbles or olivine.

As-found / cleaned comparison not yet available for this material.

Can resemble: Andesite or Slag

1 occurrence references · Hawaii

Hawaii: Kīlauea Iki — geological observation
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Gabbro

Coarse-grained dark intrusive rock, commonly with feldspar and pyroxene.

As-found / cleaned comparison not yet available for this material.

Can resemble: Diorite or Basalt

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Diorite

Coarse interlocking light and dark minerals; often a salt-and-pepper appearance.

As-found / cleaned comparison not yet available for this material.

Can resemble: Granite or Gabbro

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Rhyolite

Fine-grained silica-rich volcanic rock, sometimes with bands or larger crystals.

As-found / cleaned comparison not yet available for this material.

Can resemble: Jasper or Andesite

2 occurrence references · Utah, Nevada

Utah: Topaz Mountain Rockhound Recreation Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Nevada: Garnet Hill
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Andesite

Intermediate volcanic rock, commonly gray with small visible feldspar crystals.

As-found / cleaned comparison not yet available for this material.

Can resemble: Basalt or Rhyolite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Obsidian

Natural volcanic glass with curved fractures; sharp edges can cut skin.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: rainbow obsidian, mahogany obsidian, snowflake obsidian, apache tears, volcanic glass

Can resemble: Slag or Flint

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Pumice

Highly porous volcanic glass; some dry specimens float.

As-found / cleaned comparison not yet available for this material.

Can resemble: Scoria or Slag

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Scoria

Bubble-rich volcanic rock, often dark red or black and denser than pumice.

As-found / cleaned comparison not yet available for this material.

Can resemble: Pumice or Slag

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Tuff

Consolidated volcanic ash, sometimes with visible pumice or crystal fragments.

As-found / cleaned comparison not yet available for this material.

Can resemble: Sandstone or Rhyolite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Igneous rocks

Pegmatite

Exceptionally coarse crystalline rock; many granitic examples contain quartz, feldspar and mica.

As-found / cleaned comparison not yet available for this material.

Can resemble: Granite or Gneiss

1 occurrence references · Colorado

Colorado: Pike–San Isabel National Forests
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Quartzite

Fused quartz-rich rock derived from sandstone; grains are tightly interlocked.

As-found / cleaned comparison not yet available for this material.

Can resemble: Sandstone or Marble

1 occurrence references · Wisconsin

Wisconsin: Quartz Hill — surface specimens only
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Marble

Recrystallized carbonate rock with a sugary or interlocking texture.

As-found / cleaned comparison not yet available for this material.

Can resemble: Quartzite or Limestone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Slate

Fine-grained rock with flat cleavage planes produced during metamorphism.

As-found / cleaned comparison not yet available for this material.

Can resemble: Shale or Phyllite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Phyllite

Fine metamorphic rock with a silky sheen and commonly wavy cleavage.

As-found / cleaned comparison not yet available for this material.

Can resemble: Slate or Schist

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Schist

Visible aligned platy minerals, commonly mica, create a sparkling foliated texture.

As-found / cleaned comparison not yet available for this material.

Can resemble: Gneiss or Phyllite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Gneiss

Coarse rock with contrasting light and dark mineral bands.

As-found / cleaned comparison not yet available for this material.

Can resemble: Granite or Schist

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Serpentinite

Serpentine-rich rock often green and mottled. Do not cut or crush unidentified fibrous material.

As-found / cleaned comparison not yet available for this material.

Can resemble: Jade or Greenstone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Metamorphic rocks

Greenstone

Broad rock name for altered greenish volcanic rocks; not always gem-quality material.

As-found / cleaned comparison not yet available for this material.

Can resemble: Serpentinite or Basalt

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Quartz

Glassy mineral that commonly forms six-sided prisms; color varieties share the same mineral identity.

As found · in the mudCleaned · still rough
Quartz · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: rock crystal, milky quartz, smoky quartz, rose quartz, terminated quartz, herkimer diamond, drusy quartz

Can resemble: Calcite or Topaz

14 occurrence references · Connecticut, Wisconsin, Maine, New Hampshire, Missouri, Colorado, Utah, California, Alaska, Montana

Connecticut: Case Quarries — permitted group visits
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Wisconsin: Quartz Hill — surface specimens only
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Maine: Lord Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

New Hampshire: Moat Mountain Mineral Site
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Missouri: Sheffler Rock Shop & Geode Mine
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Missouri: Mark Twain National Forest — Potosi District
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Colorado: Pike–San Isabel National Forests
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Colorado: Rio Grande National Forest
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Maine: Deer Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Topaz Mountain Rockhound Recreation Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Dugway Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Wiley Well District Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Alaska: Independence Mine State Historical Park
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Montana: Libby Creek Recreational Gold Panning Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Amethyst

Purple quartz; lighting, coatings and glass can mislead a photo identification.

As found · in the mudCleaned · still rough
Amethyst · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Can resemble: Fluorite or Glass

2 occurrence references · Maine, Utah

Maine: Deer Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Dugway Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Citrine

Yellow to orange quartz; natural versus treated color is not reliably determined from a photo.

As-found / cleaned comparison not yet available for this material.

Can resemble: Calcite or Glass

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Chalcedony

Fine-grained silica, often translucent with a waxy luster.

As-found / cleaned comparison not yet available for this material.

Can resemble: Opal or Calcite

6 occurrence references · New Mexico, California, Missouri, Arizona, Utah

New Mexico: Rockhound State Park — main unit
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Savahia Peak chalcedony wash
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Missouri: Sheffler Rock Shop & Geode Mine
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Arizona: Black Hills Rockhound Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Dugway Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Wiley Well District Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Agate

Chalcedony commonly showing bands or patterned inclusions; trade varieties need context.

As found · in the mudCleaned · still rough
Agate · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: moss agate, plume agate, dendritic agate, fire agate, lake superior agate, fairburn agate

Can resemble: Jasper or Chert

5 occurrence references · Minnesota, Nebraska, Colorado, Arizona, California

Minnesota: Soo Line Pit — chamber agate permit
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Nebraska: Oglala National Grassland — surface rock search
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Colorado: Rio Grande National Forest
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Arizona: Black Hills Rockhound Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Wiley Well District Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Jasper

Opaque patterned silica; trade names frequently describe appearance rather than a separate mineral.

As found · in the mudCleaned · still rough
Jasper · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Can resemble: Chert or Rhyolite

2 occurrence references · New Mexico, Colorado

New Mexico: Rockhound State Park — main unit
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Colorado: Rio Grande National Forest
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Carnelian

Orange to red translucent chalcedony.

As-found / cleaned comparison not yet available for this material.

Can resemble: Jasper or Glass

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Opal

Hydrated silica, ranging from common opaque material to precious play-of-color.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: common opal, precious opal, fire opal

Can resemble: Chalcedony or Glass

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Feldspar

Common rock-forming mineral group with two prominent cleavage directions.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: orthoclase, microcline, plagioclase, amazonite, moonstone, labradorite, sunstone

Can resemble: Quartz or Calcite

5 occurrence references · Maine, New Hampshire, Oregon, Colorado

Maine: Lord Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

New Hampshire: Moat Mountain Mineral Site
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Oregon: Oregon Sunstone Public Collection Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Colorado: Pike–San Isabel National Forests
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Maine: Deer Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Mica

Minerals that split into thin, reflective sheets.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: muscovite, biotite, lepidolite

Can resemble: Hematite or Gold

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Calcite

Common carbonate mineral with rhombohedral cleavage; many colors and habits.

As found · in the mudCleaned · still rough
Calcite · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Can resemble: Quartz or Dolomite

1 occurrence references · Missouri

Missouri: Sheffler Rock Shop & Geode Mine
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Dolomite

Carbonate mineral, often pale rhombohedral crystals; differs from dolostone, the rock.

As-found / cleaned comparison not yet available for this material.

Can resemble: Calcite or Quartz

2 occurrence references · Missouri

Missouri: Mark Twain National Forest — Potosi District
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Missouri: Mark Twain National Forest — Eleven Point District
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Fluorite

Variable colors, commonly cubic crystals; color alone does not distinguish it.

As found · in the mudCleaned · still rough
Fluorite · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Can resemble: Amethyst or Calcite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Gypsum

Soft sulfate mineral; transparent crystals are often called selenite.

As-found / cleaned comparison not yet available for this material.

Gypsum species reference — Mindat

Related names and varieties: selenite, satin spar, alabaster

Can resemble: Calcite or Quartz

4 occurrence references · Oklahoma, Utah, New Mexico

Oklahoma: Salt Plains National Wildlife Refuge — crystal dig
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: South Wash, Wayne County
published occurrence. Species occurrence only; gypsum variety and collecting access are not established by this reference.
MSA Handbook of Mineralogy — gypsum

Oklahoma: Great Salt Plains, Alfalfa County
published occurrence. Occurrence evidence; consult the refuge listing for current digging rules and season.
MSA Handbook of Mineralogy — gypsum

New Mexico: Lechuguilla Cave, Carlsbad Caverns
published occurrence. Protected cave occurrence, not a collecting destination. No digging permission is implied.
MSA Handbook of Mineralogy — gypsum

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Barite

Dense sulfate mineral, sometimes bladed, tabular or rose-shaped.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: rose rock

Can resemble: Gypsum or Calcite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Halite

Often cubic, transparent to white salt mineral. Never taste unknown specimens.

As-found / cleaned comparison not yet available for this material.

Can resemble: Calcite or Fluorite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Garnet

Crystal group often forming equant many-faced crystals; not all garnets are red.

As found · in the mudCleaned · still rough
Garnet · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: almandine, spessartine, grossular, pyrope, andradite, uvarovite

Can resemble: Ruby or Spinel

5 occurrence references · Massachusetts, Maine, Nevada, California

Massachusetts: Betts Mine at Earthdance
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Maine: Lord Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Maine: Deer Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Nevada: Garnet Hill
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Chambless Rock Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Corundum

Aluminum oxide mineral; ruby and sapphire are its gemstone varieties.

As-found / cleaned comparison not yet available for this material.

Can resemble: Garnet or Spinel

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Ruby

Red corundum. Photos cannot establish authenticity, treatment or gem value.

As found · in the mudCleaned · still rough
Ruby · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Related names and varieties: rubies

Can resemble: Garnet or Spinel

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Sapphire

Gem corundum in colors other than ruby red; blue is familiar but not universal.

As found · in the mudCleaned · still rough
Sapphire · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Can resemble: Spinel or Quartz

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Beryl

Commonly hexagonal crystals; includes aquamarine and emerald varieties.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: aquamarine, morganite, heliodor, red beryl

Can resemble: Quartz or Tourmaline

1 occurrence references · Maine

Maine: Deer Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Emerald

Green gem variety of beryl; color by itself cannot confirm emerald.

As-found / cleaned comparison not yet available for this material.

Can resemble: Fluorite or Green glass

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Tourmaline

Often elongated striated crystals; available in many colors.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: schorl, elbaite

Can resemble: Beryl or Hornblende

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Topaz

Often prismatic, glassy crystals; clear examples resemble quartz.

As-found / cleaned comparison not yet available for this material.

Can resemble: Quartz or Beryl

2 occurrence references · Maine, Utah

Maine: Lord Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Topaz Mountain Rockhound Recreation Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Diamond

Often rounded natural crystal faces with strong luster. A photo cannot authenticate a diamond.

As-found / cleaned comparison not yet available for this material.

Can resemble: Quartz or Topaz

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Olivine

Greenish silicate grains common in some volcanic rocks; gem-quality olivine is peridot.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: peridot

Can resemble: Epidote or Glass

1 occurrence references · Hawaii

Hawaii: Kīlauea Iki — geological observation
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Pyrite

Brassy metallic mineral, often cubic crystals; commonly confused with gold.

As-found / cleaned comparison not yet available for this material.

Can resemble: Gold or Chalcopyrite

1 occurrence references · Massachusetts

Massachusetts: Betts Mine at Earthdance
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Gold

Yellow native metal; reflective mica and sulfide minerals can imitate it in photographs.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: placer gold, gold-bearing quartz

Can resemble: Pyrite or Mica

4 occurrence references · Alaska, Montana

Alaska: Nome Creek Public Panning Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Alaska: Jack Wade Creek Public Panning Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Alaska: Independence Mine State Historical Park
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Montana: Libby Creek Recreational Gold Panning Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Hematite

Iron oxide with varied metallic, earthy or botryoidal forms.

As-found / cleaned comparison not yet available for this material.

Can resemble: Magnetite or Ironstone

1 occurrence references · California

California: Chambless Rock Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Magnetite

Dark iron oxide, typically strongly magnetic; magnetism alone does not prove a meteorite.

As-found / cleaned comparison not yet available for this material.

Can resemble: Hematite or Slag

1 occurrence references · California

California: Chambless Rock Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Galena

Dense lead sulfide, often with cubic cleavage. Wash hands after handling; avoid dust.

As-found / cleaned comparison not yet available for this material.

Can resemble: Hematite or Pyrite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Malachite

Green copper carbonate, often banded or botryoidal. Avoid specimen dust.

As-found / cleaned comparison not yet available for this material.

Can resemble: Serpentine or Dyed stone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Azurite

Blue copper carbonate, sometimes associated with malachite.

As-found / cleaned comparison not yet available for this material.

Can resemble: Lapis lazuli or Dyed stone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Turquoise

Opaque blue-green phosphate; dyed substitutes are common.

As-found / cleaned comparison not yet available for this material.

Can resemble: Dyed howlite or Chrysocolla

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Jade

Gem name for nephrite or jadeite; many other green rocks are sold under similar names.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: nephrite, jadeite

Can resemble: Serpentinite or Quartzite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Rhodonite

Pink manganese silicate, often with dark veins.

As-found / cleaned comparison not yet available for this material.

Can resemble: Rhodochrosite or Rose quartz

1 occurrence references · Massachusetts

Massachusetts: Betts Mine at Earthdance
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Rhodochrosite

Pink manganese carbonate, often banded or rhombohedral.

As-found / cleaned comparison not yet available for this material.

Can resemble: Rhodonite or Calcite

1 occurrence references · Massachusetts

Massachusetts: Betts Mine at Earthdance
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Staurolite

Brown metamorphic mineral sometimes forming cross-shaped twins.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: fairy stones

Can resemble: Garnet or Ironstone

1 occurrence references · Virginia

Virginia: Fairy Stone State Park — designated hunt area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Kyanite

Often blue bladed crystals; other colors occur.

As-found / cleaned comparison not yet available for this material.

Can resemble: Tourmaline or Sillimanite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Epidote

Often pistachio-green crystals or granular masses.

As-found / cleaned comparison not yet available for this material.

Can resemble: Olivine or Tourmaline

1 occurrence references · California

California: Chambless Rock Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Vivianite

Soft hydrated iron phosphate, often blue to blue-green in prismatic or flattened crystals. Color may darken with oxidation; handle gently. A photograph alone cannot confirm it.

As found · in the mudCleaned · still rough
Vivianite · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Vivianite mineral reference — Mindat / Hudson Institute of Mineralogy

Related names and varieties: vivian crystals

Can resemble: Fluorite or Apatite or Tourmaline

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Apatite

Variable-color phosphate that can resemble several gemstones.

As-found / cleaned comparison not yet available for this material.

Can resemble: Beryl or Fluorite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Fossils & structures

Petrified wood

Mineral-replaced wood preserving grain, rings or cellular structure.

As-found / cleaned comparison not yet available for this material.

Related names and varieties: agatized wood, opalized wood, palmoxylon, petrified palmwood

Can resemble: Banded chert or Ironstone

1 occurrence references · Colorado

Colorado: Rio Grande National Forest
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Fossils & structures

Geode

A cavity-bearing rock, commonly with a crystal-lined interior; not a mineral species.

As-found / cleaned comparison not yet available for this material.

Can resemble: Concretion or Thunderegg

3 occurrence references · Missouri, Utah, California

Missouri: Sheffler Rock Shop & Geode Mine
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Utah: Dugway Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

California: Wiley Well District Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Fossils & structures

Thunderegg

A volcanic nodule often containing silica fillings; not every example is hollow.

As-found / cleaned comparison not yet available for this material.

Can resemble: Geode or Concretion

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Fossils & structures

Concretion

A cemented sedimentary nodule, sometimes containing fossils; not always hollow.

As-found / cleaned comparison not yet available for this material.

Can resemble: Geode or Ironstone

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Look-alikes

Slag

Human-made smelting or industrial waste; bubbles, glass and metal can resemble volcanic rocks or meteorites.

As-found / cleaned comparison not yet available for this material.

Can resemble: Basalt or Obsidian

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Look-alikes

Glass

Human-made glass may imitate gems or obsidian; provenance matters.

As-found / cleaned comparison not yet available for this material.

Can resemble: Quartz or Obsidian

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Selenite

Related mineral / family: Gypsum

Transparent crystalline gypsum. Satin spar is the fibrous, silky variety often sold under the same name.

As found · in the mudCleaned · still rough
Selenite · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Selenite variety reference — Mindat

Can resemble: Calcite or Quartz

1 occurrence references · Oklahoma

Oklahoma: Salt Plains National Wildlife Refuge — crystal dig
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Satin spar gypsum

Related mineral / family: Gypsum

Fibrous gypsum with a silky shine. A shop label saying selenite may refer to this variety.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Selenite or Fibrous calcite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Alabaster gypsum

Related mineral / family: Gypsum

Fine-grained, massive gypsum used for carving; the trade name alabaster is also used for some calcite materials.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Calcite or Marble

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Rose quartz

Related mineral / family: Quartz

Pink quartz, commonly massive rather than sharply crystallized.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Calcite or Glass

1 occurrence references · Utah

Utah: Dugway Geode Beds
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Milky quartz

Related mineral / family: Quartz

White cloudy quartz, commonly colored by microscopic inclusions.

As found · in the mudCleaned · still rough
Quartz · illustrative example. Not a verified find or a guaranteed appearance. Dirt, staining and natural variation can hide identifying features. Cleaning does not create crystal faces or polish.

Identify the material before cleaning. These pictures are not cleaning instructions; delicate minerals may be damaged by water, scrubbing or chemicals.

Mineralogical Society of America — mineral reference index

Can resemble: Feldspar or Calcite

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Moonstone

Related mineral / family: Feldspar

Feldspar exhibiting a floating optical sheen. Mineral composition varies with the material sold under this gem name.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Opal or Glass

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Sunstone

Related mineral / family: Feldspar

A feldspar gem name; some examples show reflective inclusions. Oregon sunstone is a particular material and locality association.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Other feldspar or Glass

1 occurrence references · Oregon

Oregon: Oregon Sunstone Public Collection Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Almandine

Related mineral / family: Garnet

An iron-rich garnet species commonly dark red to brown.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Other garnet or Ruby

1 occurrence references · Nevada

Nevada: Garnet Hill
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Lepidolite mica

Related mineral / family: Mica

A name used for lithium-rich micas, often lilac or pink; modern species classification needs composition.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Muscovite or Pink feldspar

No linked local occurrence yet. This reference is available for research; no state or collecting permission is inferred.

Explore related catalog listings →

Compare a specimen photo →
Minerals & gems

Phenakite

Beryllium silicate, sometimes clear crystals that resemble quartz.

As-found / cleaned comparison not yet available for this material.

Mineralogical Society of America — mineral reference index

Can resemble: Quartz or Topaz

1 occurrence references · Maine

Maine: Lord Hill Mineral Collecting Area
reported locality. Reported material at this locality; this is not a complete state inventory or a guarantee of finds. Check the listing for access rules.
Catalog locality source

Explore related catalog listings →

Compare a specimen photo →

Geology references

NPS rock and mineral introductionUSGS Cooperative National Geologic Map — lower 48NPS state geological maps — all 50 statesMSA Handbook of Mineralogy — global species index ↗

Descriptions are orientation aids, not lab identifications. Never taste unknown specimens, breathe dust or damage a specimen to test it.