Rock Identifier

Category

Organic Gemstone (Not A Rock Or Mineral)

Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.

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

Calcite

Calcite (CaCO₃, Calcium Carbonate)

Gneiss (Gneiss (Metamorphic rock)) — metamorphic

Gneiss

Gneiss (Metamorphic rock)

Foliated Metamorphic Rock (likely Gneiss or Schist) (Gneissic Metamorphic Rock) — metamorphic

Foliated Metamorphic Rock (likely Gneiss or Schist)

Gneissic Metamorphic Rock

Massive Quartz (Milky or Gray) (Silicon Dioxide (SiO2)) — mineral

Massive Quartz (Milky or Gray)

Silicon Dioxide (SiO2)

Chert (variously known as Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variously known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Basalt (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Quartz with Iron Stains (Quartz (SiO2) with iron oxide/hydroxide staining) — Mineral

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Petrified Wood (Silicified Wood (primarily Chalcedony/Quartz, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Chalcedony/Quartz, SiO2)

Ammonite Fossil (Ammonoidea (Calcium carbonate - CaCO3)) — sedimentary

Ammonite Fossil

Ammonoidea (Calcium carbonate - CaCO3)

Tufa (Calcareous Tufa (Calcium Carbonate, CaCO3)) — sedimentary

Tufa

Calcareous Tufa (Calcium Carbonate, CaCO3)

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Chert (often referred to as Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often referred to as Flint)

Chert (Microcrystalline Quartz, SiO2)

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

Chert (Chert / Flint)

Silicon Dioxide (SiO2)

Chert (varieties include Flint or Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (varieties include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Dolomite (Dolomite (CaMg(CO3)2)) — Mineral

Dolomite

Dolomite (CaMg(CO3)2)

Yellow Quartzite (River Pebble) (Quartzite (mainly SiO2)) — metamorphic

Yellow Quartzite (River Pebble)

Quartzite (mainly SiO2)

Granite (Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)) — igneous

Granite

Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)

Granite (Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)

Lapis Lazuli (Tumbled Specimen) (Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)) — metamorphic

Lapis Lazuli (Tumbled Specimen)

Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)

Rhodochrosite (Manganese carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese carbonate (MnCO3)

Quartz (Milky Quartz vein fragment) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky Quartz vein fragment)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Sandstone (Arenite (SiO2 based with various mineral cements)) — sedimentary

Sandstone

Arenite (SiO2 based with various mineral cements)

Sandstone (with Concretion) (Arenite / Quartzose Sandstone) — sedimentary

Sandstone (with Concretion)

Arenite / Quartzose Sandstone

Botryoidal Chalcedony (Desert Rose / Agate) (Silicon Dioxide (SiO₂)) — Mineral variant

Botryoidal Chalcedony (Desert Rose / Agate)

Silicon Dioxide (SiO₂)

Mineral variant

Turquoise (beads) (Turquoise; CuAl6(PO4)4(OH)8·4H2O) — Mineral

Turquoise (beads)

Turquoise; CuAl6(PO4)4(OH)8·4H2O

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Petrified Wood (Silicon Dioxide (SiO2) permineralized organic matter) — sedimentary

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

Bauxite (Bauxite (principal ore of aluminum, primarily Al(OH)3)) — sedimentary

Bauxite

Bauxite (principal ore of aluminum, primarily Al(OH)3)

Epidote (Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)) — mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

Blue Quartzite (Quartzite (specifically a variety enriched with blue-coloring minerals)) — Metamorphic Rock

Blue Quartzite

Quartzite (specifically a variety enriched with blue-coloring minerals)

Metamorphic Rock

Carved Mottled Greenish-Yellow Crystal/Glass Object (Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.) — Man-made Object/Uncertain Mineral

Carved Mottled Greenish-Yellow Crystal/Glass Object

Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.

Man-made Object/Uncertain Mineral

Pearl (Calcium carbonate (CaCO3) - Aragonite/Calcite variety) — mineral

Pearl

Calcium carbonate (CaCO3) - Aragonite/Calcite variety

Amethyst (Quartz (SiO2) with trace iron impurities) — Mineral

Amethyst

Quartz (SiO2) with trace iron impurities

Turquoise (Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)) — Mineral

Turquoise

Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)

Greywacke (River Pebble with Quartz Veins) (Greywacke (Indurated Sandstone); Veins: SiO2 (Quartz)) — sedimentary

Greywacke (River Pebble with Quartz Veins)

Greywacke (Indurated Sandstone); Veins: SiO2 (Quartz)

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

Mica Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

Olivine (Peridot) (Magnesium Iron Silicate (Mg, Fe)2SiO4) — Mineral

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Granodiorite (Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)) — igneous

Granodiorite

Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)

Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

Granite (Granite (Phaneritic Quartz-Feldspar Plutonic Rock)) — igneous

Granite

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)