Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Green Quartzite (River Stone) (Metamorphic Quartz (SiO2) with inclusions (typically Fuchsite or Chlorite)) — metamorphic

Green Quartzite (River Stone)

Metamorphic Quartz (SiO2) with inclusions (typically Fuchsite or Chlorite)

Basalt (Arrowhead form) (Extrusive mafic igneous rock) — igneous

Basalt (Arrowhead form)

Extrusive mafic igneous rock

Vesicular Basalt (or Scoria) (Vesicular Basalt) — igneous

Vesicular Basalt (or Scoria)

Vesicular Basalt

Quartz (Milky/Clear Variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Clear Variety)

Silicon Dioxide (SiO2)

Basalt (Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)) — Igneous

Basalt

Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)

Basalt (Basalt (Mafic igneous rock)) — igneous

Basalt

Basalt (Mafic igneous rock)

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Basalt (Crushed Roadstone) (Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Basalt (Crushed Roadstone)

Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Clear Quartz / Rock Crystal (Silicon Dioxide (SiO2)) — mineral

Clear Quartz / Rock Crystal

Silicon Dioxide (SiO2)

Basalt (River-worn Specimen) (Extrusive Mafic Igneous Rock) — igneous

Basalt (River-worn Specimen)

Extrusive Mafic Igneous Rock

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Basalt (Stream-worn Cobble) (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt (Stream-worn Cobble)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Basalt (Weathered/Tumbled) (Extrusive Mafic Igneous Rock) — igneous

Basalt (Weathered/Tumbled)

Extrusive Mafic Igneous Rock

Quartzite with Quartz Vein (Quartzite (primarily SiO2)) — metamorphic

Quartzite with Quartz Vein

Quartzite (primarily SiO2)

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Diorite (Diorite) — igneous

Diorite

Diorite

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Quartzite (River Pebble) (SiO2 (recrystallized Quartz)) — metamorphic

Quartzite (River Pebble)

SiO2 (recrystallized Quartz)

Basalt (Basalt (composition of Plagioclase feldspar, Pyroxene, and Olivine)) — igneous

Basalt

Basalt (composition of Plagioclase feldspar, Pyroxene, and Olivine)

Pink Granite (Phaneritic Felsic Igneous Rock (composed primarily of K-feldspar, Quartz, and Biotite)) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-feldspar, Quartz, and Biotite)

Basalt (Vesicular and Scoria) (Basalt (extrusive volcanic rock)) — igneous

Basalt (Vesicular and Scoria)

Basalt (extrusive volcanic rock)

Basalt (Basalt (predominantly Plagioclase Feldspar and Pyroxene)) — igneous

Basalt

Basalt (predominantly Plagioclase Feldspar and Pyroxene)

Vesicular Basalt (Extrusive mafic igneous rock (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Vesicular Basalt

Extrusive mafic igneous rock (primarily Plagioclase Feldspar and Pyroxene)

Limonitic Quartzite (Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining) — metamorphic

Limonitic Quartzite

Metamorphosed sandstone with Limonite (FeO(OH)·nH2O) staining

Basalt Pebble (Basalt) — igneous

Basalt Pebble

Basalt

Basalt (River Stone) (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt (River Stone)

Basalt (Aphanitic Mafic Igneous Rock)

Pink Granite (Phaneritic Plutonic Rock (Granite with K-Feldspar)) — igneous

Pink Granite

Phaneritic Plutonic Rock (Granite with K-Feldspar)

Black River Stone (likely Basalt or Chert) (Basalt (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Black River Stone (likely Basalt or Chert)

Basalt (primarily Plagioclase Feldspar and Pyroxene)

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Chert (or Flint) (Chert (cryptocrystalline quartz), SiO2) — Sedimentary

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Granite (Granite (Mainly Quartz SiO2, K-Feldspar KAlSi3O8, and Plagioclase)) — igneous

Granite

Granite (Mainly Quartz SiO2, K-Feldspar KAlSi3O8, and Plagioclase)

Basalt (Polished) (Extrusive mafic igneous rock) — igneous

Basalt (Polished)

Extrusive mafic igneous rock

Ammonite Fossil in Limestone Matrix (Ammonoidea (subclass) in Calcium Carbonate (CaCO3)) — sedimentary

Ammonite Fossil in Limestone Matrix

Ammonoidea (subclass) in Calcium Carbonate (CaCO3)

Quartzite with Garnet (Garnetiferous Quartzite (SiO2 + X3Y2(SiO4)3)) — metamorphic

Quartzite with Garnet

Garnetiferous Quartzite (SiO2 + X3Y2(SiO4)3)

Chalk (Calcium Carbonate (CaCO3)) — sedimentary

Chalk

Calcium Carbonate (CaCO3)

Basalt (River Pebble) (Basalt) — igneous

Basalt (River Pebble)

Basalt

Vesicular Basalt with Secondary Mineral Inclusions (Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Vesicular Basalt with Secondary Mineral Inclusions

Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Basalt (Polished River Stone) (Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)) — Igneous

Basalt (Polished River Stone)

Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Basalt (Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)) — igneous

Basalt

Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)

Granite (Granite (Phaneritic Igneous Rock)) — igneous

Granite

Granite (Phaneritic Igneous Rock)