Rock Identifier

Category

Organic (Anthropogenic)

Browse organic (anthropogenic) specimens identified by the Rock Identifier community.

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Limonite-stained Quartzite (Quartzite with Limonite (FeO(OH)·nH2O) staining) — metamorphic

Limonite-stained Quartzite

Quartzite with Limonite (FeO(OH)·nH2O) staining

Quartzite Pebble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

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

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — metamorphic

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Yellow Jasper (Chalcedony (SiO2) with goethite or limonite inclusions) — sedimentary

Yellow Jasper

Chalcedony (SiO2) with goethite or limonite inclusions

Greenstone / Diorite (Intermediate plutonic igneous rock) — igneous

Greenstone / Diorite

Intermediate plutonic igneous rock

Quartz with Mica/Chlorite inclusions (Silicon Dioxide (SiO2) with phyllosilicate inclusions) — igneous/metamorphic mineral specimen

Quartz with Mica/Chlorite inclusions

Silicon Dioxide (SiO2) with phyllosilicate inclusions

igneous/metamorphic mineral specimen

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Chert (Nodule) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline Silica (SiO2)

Granite (Phaneritic Plutonic Felsic Rock (primarily Quartz (SiO2), Alkali Feldspar, and Plagioclase Feldspar)) — igneous

Granite

Phaneritic Plutonic Felsic Rock (primarily Quartz (SiO2), Alkali Feldspar, and Plagioclase Feldspar)

Limestone (Cliff Formation) (Limestone (predominantly CaCO3 as calcite)) — Sedimentary

Limestone (Cliff Formation)

Limestone (predominantly CaCO3 as calcite)

Chert (Nodule) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (Silicon dioxide (SiO2)) — sedimentary

Chert

Silicon dioxide (SiO2)

Granite (Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).) — igneous

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Chert (Hagstone/Gasket Rock variant) (Chert (SiO2)) — sedimentary

Chert (Hagstone/Gasket Rock variant)

Chert (SiO2)

Crinoid Stem Fossil (Class Crinoidea (Phylum Echinodermata), primarily Calcium Carbonate (CaCO3)) — sedimentary

Crinoid Stem Fossil

Class Crinoidea (Phylum Echinodermata), primarily Calcium Carbonate (CaCO3)

Chert (Nodule) (Cryptocrystalline Silica (SiO2)) — sedimentary

Chert (Nodule)

Cryptocrystalline Silica (SiO2)

Granite (Granite (a felsic intrusive igneous rock)) — Igneous

Granite

Granite (a felsic intrusive igneous rock)

Granite (Granite (a common rock type, not a single mineral; composed primarily of Quartz, Feldspar (Orthoclase and Plagioclase), and Mica (Biotite and/or Muscovite) and/or Amphibole)) — Igneous

Granite

Granite (a common rock type, not a single mineral; composed primarily of Quartz, Feldspar (Orthoclase and Plagioclase), and Mica (Biotite and/or Muscovite) and/or Amphibole)

Chert Pebble / Brachiopod Fossil Internal Mold (Silicon Dioxide (SiO2) / Fossil: Brachiopoda (generic internal mold)) — sedimentary

Chert Pebble / Brachiopod Fossil Internal Mold

Silicon Dioxide (SiO2) / Fossil: Brachiopoda (generic internal mold)

Chert (Limestone-based) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Limestone-based)

Silicon Dioxide (SiO2)

Granite (Granite (felsic intrusive igneous rock)) — igneous

Granite

Granite (felsic intrusive igneous rock)

Unakite (Epidote-Feldspar rock (specifically, a variety of granite)) — Metamorphic rock

Unakite

Epidote-Feldspar rock (specifically, a variety of granite)

Metamorphic rock

Chert (Chert (microcrystalline quartz, SiO2)) — Sedimentary

Chert

Chert (microcrystalline quartz, SiO2)

Calcite (likely a tumbled specimen) (Calcite (CaCO
3
)) — Mineral

Calcite (likely a tumbled specimen)

Calcite (CaCO 3 )

Crushed Limestone (Calcium Carbonate (CaCO3)) — Sedimentary

Crushed Limestone

Calcium Carbonate (CaCO3)

Granite (Granite (a plutonic igneous rock)) — Igneous

Granite

Granite (a plutonic igneous rock)

Chert (Chert (microcrystalline quartz)) — Sedimentary

Chert

Chert (microcrystalline quartz)

Granite (Granite (a common rock type, not a single mineral species)) — Igneous

Granite

Granite (a common rock type, not a single mineral species)

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

Chert (or Flint)

Chert (microcrystalline or cryptocrystalline quartz, SiO2)

Chert (Jasper-like) (SiO2 (Cryptocrystalline Quartz)) — Sedimentary

Chert (Jasper-like)

SiO2 (Cryptocrystalline Quartz)

Lepidolite (K(Li,Al)3(Si,Al)4O10(F,OH)2) — Mineral

Lepidolite

K(Li,Al)3(Si,Al)4O10(F,OH)2

Chert (Flint) (SiO2 (predominantly microcrystalline or cryptocrystalline quartz)) — Sedimentary rock

Chert (Flint)

SiO2 (predominantly microcrystalline or cryptocrystalline quartz)

Sedimentary rock

Chert / Flint (a variety of Chert) (Chert (SiO2)) — Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

Chert / Flint (a variety of Chert)

Chert (SiO2)

Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)

Chert (or Flint) (Chert (a cryptocrystalline variety of quartz, SiO2)) — sedimentary

Chert (or Flint)

Chert (a cryptocrystalline variety of quartz, SiO2)

Calcite (Calcite (Mineral; CaCO₃)) — Mineral

Calcite

Calcite (Mineral; CaCO₃)

Quartzite (Quartzite) — Metamorphic

Quartzite

Quartzite

Chert (varieties include Flint or Jasper) (Chert (cryptocrystalline quartz; SiO₂)) — Sedimentary

Chert (varieties include Flint or Jasper)

Chert (cryptocrystalline quartz; SiO₂)

Talc (Talc (Mg₃Si₄O₁₀(OH)₂)) — Mineral

Talc

Talc (Mg₃Si₄O₁₀(OH)₂)

Chert (Flint) (Chert (microcrystalline quartz)) — sedimentary

Chert (Flint)

Chert (microcrystalline quartz)

Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Calcite

Calcite (Calcium Carbonate, CaCO3)