Rock Identifier

Category

Organic (Mineraloid)

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

Chert (Jasper/Agate) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Agate)

Cryptocrystalline Quartz (SiO2)

Chert (Yellow Jasper/Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

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

Chert

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Fossiliferous Limestone with Crinoid stems (Limestone (CaCO3) containing Crinoidea fossils) — sedimentary

Fossiliferous Limestone with Crinoid stems

Limestone (CaCO3) containing Crinoidea fossils

Granite (Plutonic Igneous Rock (Granite)) — igneous

Granite

Plutonic Igneous Rock (Granite)

Chert (with Iron Staining) (Chert (SiO2)) — sedimentary

Chert (with Iron Staining)

Chert (SiO2)

Granite (Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Calcite (Calcium Carbonate (CaCO3)) — mineral

Calcite

Calcium Carbonate (CaCO3)

Chert (Iron-stained) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (Silicon Dioxide, SiO2)

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

Chert (Flint)

Chert (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Quartzite (Quartzite (mostly SiO2)) — metamorphic

Quartzite

Quartzite (mostly SiO2)

Coquina / Fossiliferous Limestone (Bioclastic Limestone (CaCO3)) — sedimentary

Coquina / Fossiliferous Limestone

Bioclastic Limestone (CaCO3)

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

Honey Calcite

Calcite (Calcium Carbonate, CaCO3)

Pink Quartzite (Quartzite (SiO2)) — metamorphic

Pink Quartzite

Quartzite (SiO2)

Gneiss (specifically Banded Gneiss) (Gneiss) — metamorphic

Gneiss (specifically Banded Gneiss)

Gneiss

Mookaite Jasper (Silicified Radiolarite (SiO2)) — sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2)

Chert (often called Flint or Jasper based on color) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper based on color)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Chert (Polished Gemstone / River Stone) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Polished Gemstone / River Stone)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Gray/Banded Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray/Banded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green Schist (Greenschist (composed of Chlorite, Actinolite, and Epidote)) — metamorphic

Green Schist

Greenschist (composed of Chlorite, Actinolite, and Epidote)

Echinoidea (Fossil Sea Urchin) (Echinodermata Echinoidea) — sedimentary

Echinoidea (Fossil Sea Urchin)

Echinodermata Echinoidea

Graywacke (Graywacke) — sedimentary

Graywacke

Graywacke

Chalk (Calcareous Ooze (composed primarily of coccoliths)) — Sedimentary Rock

Chalk

Calcareous Ooze (composed primarily of coccoliths)

Sedimentary Rock

Dark Igneous Rock (Likely Basalt or Diabase) (Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.) — Igneous

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

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

Chert (or Jasper)

Microcrystalline Quartz (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Common Opal or Flint variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Common Opal or Flint variant)

Microcrystalline Quartz (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

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

Chert (Quartz)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Chert (SiO2)) — sedimentary

Chert

Chert (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Quartzite (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

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

Chert / Flint

Silicon dioxide (SiO2)

Chert (often called Flint when dark) (Sedimentary cryptocrystalline quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Sedimentary cryptocrystalline quartz (SiO2)