Rock Identifier

Category

Rock (Likely Sedimentary)

Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.

Glauconite (Glauconitic Sandstone) (Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]) — sedimentary

Glauconite (Glauconitic Sandstone)

Glauconite [(K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2]

Gneiss (Metamorphic Rock) (Gneiss (high-grade regional metamorphic rock)) — metamorphic

Gneiss (Metamorphic Rock)

Gneiss (high-grade regional metamorphic rock)

River Stone (River Pebbles) (Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)) — sedimentary

River Stone (River Pebbles)

Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)

Chert (Jasper/Agate variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Graywacke (Graywacke (immature sandstone)) — sedimentary

Graywacke

Graywacke (immature sandstone)

Granite Gneiss (Gneiss (High-grade Metamorphic Rock)) — metamorphic

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Red Sandstone (Arenite with Hematite cementation) — sedimentary

Red Sandstone

Arenite with Hematite cementation

Coquina (Biogenic Limestone (Calcium Carbonate - CaCO3)) — sedimentary

Coquina

Biogenic Limestone (Calcium Carbonate - CaCO3)

Fossil Coral (Honeycomb Coral) (Favosites (extinct genus of Tabulate coral)) — sedimentary

Fossil Coral (Honeycomb Coral)

Favosites (extinct genus of Tabulate coral)

Breccia (Breccia) — sedimentary

Breccia

Breccia

Milky Quartz (Crystal Cluster) (Silicon Dioxide (SiO2) - Quartz Variety) — mineral

Milky Quartz (Crystal Cluster)

Silicon Dioxide (SiO2) - Quartz Variety

Chert (Yellow Jasper/Quartzite Pebble) (Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Yellow Jasper/Quartzite Pebble)

Microcrystalline Silicon Dioxide (SiO2)

Bituminous Coal (Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)) — sedimentary

Bituminous Coal

Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)

Red Sandstone (Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)) — sedimentary

Red Sandstone

Clastic Terrigenous Sedimentary Rock (primarily SiO2 with Fe2O3 coating)

Sandstone with Bedding Planes (Arenite (Sedimentary rock composed primarily of sand-sized minerals)) — sedimentary

Sandstone with Bedding Planes

Arenite (Sedimentary rock composed primarily of sand-sized minerals)

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

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Anthracite Coal (Anthracite (Carbon-rich metamorphic rock)) — metamorphic

Anthracite Coal

Anthracite (Carbon-rich metamorphic rock)

Jasper (Red) (Silicon Dioxide (SiO2)) — sedimentary

Jasper (Red)

Silicon Dioxide (SiO2)

Red Jasper (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — mineral

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Quartz Geode (Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity) — mineral

Quartz Geode

Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity

Mica Schist (Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)) — metamorphic

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Schist with Biotite Inclusion (Biotite-bearing Mica Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)) — metamorphic

Schist with Biotite Inclusion

Biotite-bearing Mica Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)

Clear Quartz Sphere (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz Sphere

Quartz (Silicon Dioxide, SiO2)

Mica Schist (Mica Schist (predominantly Muscovite or Biotite sheet silicates)) — metamorphic

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

River Cobble (Salt and Pepper Gneiss) (Gneiss (High-grade regional metamorphic rock)) — metamorphic

River Cobble (Salt and Pepper Gneiss)

Gneiss (High-grade regional metamorphic rock)

Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Agate (Grey Agate Slice) (Microcrystalline Quartz (SiO2)) — mineral

Agate (Grey Agate Slice)

Microcrystalline Quartz (SiO2)

Common Opal (Hydrated silica (SiO2 " nH2O)) — mineral

Common Opal

Hydrated silica (SiO2 " nH2O)

Agate (specifically Waterline or Onyx-type Agate) (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Agate (specifically Waterline or Onyx-type Agate)

Silicon Dioxide (SiO2) - variety Chalcedony

Banded Agate (River Stone) (Agate (Silicon Dioxide - SiO2)) — mineral

Banded Agate (River Stone)

Agate (Silicon Dioxide - SiO2)

Banded Chert in Matrix (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert in Matrix

Microcrystalline Quartz (SiO2)

Quartz Geode (Smoky Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz Geode (Smoky Quartz)

Silicon Dioxide (SiO2)

Granite Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Granite Gneiss

Gneiss (High-grade metamorphic rock)

Specular Hematite (Specularite (Fe2O3)) — mineral

Specular Hematite

Specularite (Fe2O3)

Beads (likely glass or man-made material) (N/A (artificial material)) — Man-made material, not a natural rock or mineral specimen

Beads (likely glass or man-made material)

N/A (artificial material)

Man-made material, not a natural rock or mineral specimen

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper) (Chalcedony (SiO₂)) — Mineral (or mineraloid if microcrystalline)

Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)

Chalcedony (SiO₂)

Mineral (or mineraloid if microcrystalline)

Chert (Jasper/Flint variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2)

Rough Quartz (or Quartzite pebble) (Silicon Dioxide (SiO2)) — mineral

Rough Quartz (or Quartzite pebble)

Silicon Dioxide (SiO2)

Banded Gneiss (Gneiss (quartz-feldspar-biotite metamorphic rock)) — metamorphic

Banded Gneiss

Gneiss (quartz-feldspar-biotite metamorphic rock)

Arkosic Sandstone (Arkose) — sedimentary

Arkosic Sandstone

Arkose

Sandstone (Arenite (primarily Quartz, SiO2)) — sedimentary

Sandstone

Arenite (primarily Quartz, SiO2)

Gastropod Steinkern (Fossilized Snail Cast) (Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)) — Sedimentary

Gastropod Steinkern (Fossilized Snail Cast)

Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)