Rock Identifier

Category

Organic (Geological Relative)

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

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Pink Granite (Phaneritic Felsic Igneous Rock) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock

Diorite (Salt and Pepper Rock) (Diorite) — igneous

Diorite (Salt and Pepper Rock)

Diorite

Chert (Grey-Green Flint) (Microcrystalline silicon dioxide (SiO2)) — sedimentary

Chert (Grey-Green Flint)

Microcrystalline silicon dioxide (SiO2)

Fossilized Coral (Petoskey Stone / Favosites) (Hexagonaria percarinata / Favosites sp.) — fossil

Fossilized Coral (Petoskey Stone / Favosites)

Hexagonaria percarinata / Favosites sp.

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

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

Chert (Flint)

Chert (microcrystalline quartz)

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

Chert (or Flint)

SiO2 (predominantly microcrystalline quartz)

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

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

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Fossiliferous Limestone (Calcium Carbonate (CaCO3) with Bioclastic inclusions) — sedimentary

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Bioclastic inclusions

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

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads) (Obsidian (volcanic glass, predominantly SiO2 with various impurities)) — Igneous

Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads)

Obsidian (volcanic glass, predominantly SiO2 with various impurities)

Halite (Rock Salt) (Halite; NaCl (Sodium Chloride)) — Mineral

Halite (Rock Salt)

Halite; NaCl (Sodium Chloride)

Sandstone (with possibly iron oxides and other minerals) (Sandstone) — Sedimentary rock

Sandstone (with possibly iron oxides and other minerals)

Sandstone

Sedimentary rock

Laterite (Laterite (no specific mineral formula as it's a rock type)) — Sedimentary

Laterite

Laterite (no specific mineral formula as it's a rock type)

Fossiliferous limestone (Calcite-rich limestone (CaCO₃), containing fossil shell or coral fragments) — sedimentary

Fossiliferous limestone

Calcite-rich limestone (CaCO₃), containing fossil shell or coral fragments

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (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)

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

Chert (Nodule)

Microcrystalline Silica (SiO2)

Fossilized Shell Impression / Siltstone Fossil (Bivalvia / Brachiopoda mold in Siltstone) — fossil

Fossilized Shell Impression / Siltstone Fossil

Bivalvia / Brachiopoda mold in Siltstone

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

Limestone (Cliff Formation)

Limestone (predominantly CaCO3 as calcite)

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 (Silicon dioxide (SiO2)) — sedimentary

Chert

Silicon dioxide (SiO2)

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

Granite

Granite (a felsic intrusive igneous rock)

Quartzite (Metamorphic Quartz Sandstone) — metamorphic

Quartzite

Metamorphic Quartz Sandstone

Chert (Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)) — Sedimentary

Chert

Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)

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

Granite

Granite (felsic intrusive igneous rock)

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

Chert

Chert (microcrystalline quartz, SiO2)

Weathered fossiliferous limestone fragment, possibly fossil coral or shell material (Indeterminate carbonate fossil in calcitic limestone; likely composed mainly of calcite (CaCO₃), but species identification is not possible from this image alone) — fossil

Weathered fossiliferous limestone fragment, possibly fossil coral or shell material

Indeterminate carbonate fossil in calcitic limestone; likely composed mainly of calcite (CaCO₃), but species identification is not possible from this image alone

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

Granite

Granite (a plutonic igneous rock)

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

Chert (or Flint)

Chert (microcrystalline or cryptocrystalline quartz, SiO2)

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

Granite

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

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

Chert (Jasper-like)

SiO2 (Cryptocrystalline Quartz)

Chert (or possibly Flint) (SiO2 (Silicon Dioxide)) — Sedimentary Rock

Chert (or possibly Flint)

SiO2 (Silicon Dioxide)

Sedimentary Rock

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)

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)

Chert (or possibly Flint) (Chert (variant: Flint)) — Sedimentary

Chert (or possibly Flint)

Chert (variant: Flint)