Rock Identifier

Category

Organic Gemstone (Mineraloid)

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

Learn about Organic Gemstone (Mineraloid) in the encyclopedia

Jet

Red Chert (Jasper) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Chert (Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled brown agate (likely moss or plume agate) (Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possibly mineral inclusions) — gemstone

Tumbled brown agate (likely moss or plume agate)

Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possibly mineral inclusions

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (specifically Flint or Novaculite variant) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (specifically Flint or Novaculite variant)

Chert (Microcrystalline Quartz, SiO2)

Likely weathered flint or chert fragment (Cryptocrystalline quartz (SiO₂), possibly siliceous chert/flint) — sedimentary

Likely weathered flint or chert fragment

Cryptocrystalline quartz (SiO₂), possibly siliceous chert/flint

Fossil bivalve shell (Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features) — fossil

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Pink Opal (Amorphous Hydrous Silica (SiO2·nH2O)) — mineral

Pink Opal

Amorphous Hydrous Silica (SiO2·nH2O)

Moss Agate (Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron) — mineral

Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron

Moss Agate (Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of manganese or iron oxide

Amber (Fossilized Tree Resin (Succinate)) — mineral

Amber

Fossilized Tree Resin (Succinate)

Green Moss Agate (Silicon Dioxide (SiO2) with Mineral Inclusions) — sedimentary

Green Moss Agate

Silicon Dioxide (SiO2) with Mineral Inclusions

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turquoise, Pearl, and Coral Necklace (CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)) — mineral

Turquoise, Pearl, and Coral Necklace

CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)

Chert (variations include Flint) (Sedimentary cryptocrystalline quartz (SiO2)) — sedimentary

Chert (variations include Flint)

Sedimentary cryptocrystalline quartz (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Paleoxylon (SiO2)) — fossil

Petrified Wood

Silicified Paleoxylon (SiO2)

Chert (often called Flint in dark varieties) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint in dark varieties)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Polished banded agate (likely picture jasper or petrified wood) (Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions) — gemstone

Polished banded agate (likely picture jasper or petrified wood)

Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions

Red Jasper (Quartz (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper

Quartz (SiO2) with iron oxide inclusions

Jasper (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Chert (Yellow/Tan) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow/Tan)

Microcrystalline Quartz (SiO2)

Tumbled brown jasper (likely common jasper or chert) (Microcrystalline quartz, SiO₂, chiefly chalcedony/quartz with iron-oxide impurities) — mineral

Tumbled brown jasper (likely common jasper or chert)

Microcrystalline quartz, SiO₂, chiefly chalcedony/quartz with iron-oxide impurities

Pearl jewelry (Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)) — gemstone

Pearl jewelry

Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)

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

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

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

Chert (or Chalcedony)

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Jasper (Silicon Dioxide (SiO2) with iron oxide impurities) — sedimentary

Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Yellow Jasper / Chert (Jasper (Silica/Quartz) - SiO2) — sedimentary

Yellow Jasper / Chert

Jasper (Silica/Quartz) - SiO2

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper) (Cryptocrystalline quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Cryptocrystalline quartz (SiO2)

Chert (White Chert or Flint) (Microcrystalline or cryptocrystalline quartz (SiO2)) — sedimentary

Chert (White Chert or Flint)

Microcrystalline or cryptocrystalline quartz (SiO2)

Chert (specifically Red Chert / Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Red Chert / Jasper)

Silicon Dioxide (SiO2)

Pearl (Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)) — gemstone

Pearl

Nacre (aragonite, CaCO₃, in an organic conchiolin matrix)

Banded Agate (Dyed) (SiO2 (Silicon Dioxide / Microcrystalline Quartz)) — mineral

Banded Agate (Dyed)

SiO2 (Silicon Dioxide / Microcrystalline Quartz)

Chert (specifically Tan Chert or Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Tan Chert or Flint)

Silicon Dioxide (SiO2)

Dyed Agate (Tumbled) (Silicon Dioxide (Chalcedony variety, artificially dyed)) — gemstone

Dyed Agate (Tumbled)

Silicon Dioxide (Chalcedony variety, artificially dyed)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Chert (Jasper/Jasperoid) (Chert (chemically precipitated microcrystalline Quartz, SiO2)) — sedimentary

Chert (Jasper/Jasperoid)

Chert (chemically precipitated microcrystalline Quartz, SiO2)