Rock Identifier

Category

Organic Crystal (Mineraloid)

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

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

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

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with fossil inclusions

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Precious Red Coral (Corallium rubrum (Calcium Carbonate, CaCO3)) — mineral

Precious Red Coral

Corallium rubrum (Calcium Carbonate, CaCO3)

Fossilized Wood (Petrified Wood) and Associated Rocks (Silicified Wood / Xylopal) — fossil

Fossilized Wood (Petrified Wood) and Associated Rocks

Silicified Wood / Xylopal

Moss Agate (Silicon dioxide (SiO2) with inclusions) — Mineral

Moss Agate

Silicon dioxide (SiO2) with inclusions

Chert (Flint) (Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)) — sedimentary

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz - SiO2)

Chert (Flint) (Microcrystalline silica (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline silica (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Coral Fossil (Agatized Coral or Petoskey Stone) (Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)) — Sedimentary/Fossil

Coral Fossil (Agatized Coral or Petoskey Stone)

Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)

Sedimentary/Fossil

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

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone (Carved Statue) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (Carved Statue)

Calcium Carbonate (CaCO3)

Pyrite in Shale (Iron Sulfide (FeS2) in Argillaceous Shale) — sedimentary

Pyrite in Shale

Iron Sulfide (FeS2) in Argillaceous Shale

Fossiliferous Limestone (Biogenic Sedimentary Rock / CaCO3 with fossil fragments) — sedimentary

Fossiliferous Limestone

Biogenic Sedimentary Rock / CaCO3 with fossil fragments

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Chalcedony/Common Opal) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Common Opal)

Microcrystalline Quartz (SiO2)

Pyrite (Fool's Gold) Cube (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold) Cube

Iron Sulfide (FeS2)

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

Flint (Chert)

Silicon Dioxide (SiO2)

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Chert with Quartz Veining (Microcrystalline silica (SiO2)) — sedimentary

Chert with Quartz Veining

Microcrystalline silica (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

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

Flint (Chert Node)

Silicon Dioxide (SiO2)

Pyrite Geode (Iron Disulfide (FeS2)) — mineral

Pyrite Geode

Iron Disulfide (FeS2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Chert (or Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (or Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (White/Gray variety) (Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)) — sedimentary

Chert (White/Gray variety)

Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

Chert (Nodule) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Nodule)

Chert (Silicon Dioxide, SiO2)

Tufa Rock and Tumbled Gemstones (Calcareous Tufa (Calcium Carbonate, CaCO3)) — sedimentary

Tufa Rock and Tumbled Gemstones

Calcareous Tufa (Calcium Carbonate, CaCO3)

Chert (and Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (and Chalcedony)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Carbonate Rock (CaCO3 with organic inclusions)) — sedimentary

Fossiliferous Limestone

Carbonate Rock (CaCO3 with organic inclusions)

Petrified Wood (Agatized/Silicified Wood) (Silicified Paleoxylon (primarily SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Paleoxylon (primarily SiO2)

Limestone Pebble (Sedimentary carbonate rock (CaCO3)) — sedimentary

Limestone Pebble

Sedimentary carbonate rock (CaCO3)

Banded Limestone (Calcareous sedimentary rock (CaCO3)) — sedimentary

Banded Limestone

Calcareous sedimentary rock (CaCO3)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Jasper Agate (Silicon dioxide (SiO2)) — mineral

Jasper Agate

Silicon dioxide (SiO2)