Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Learn about Organic Gemstone in the encyclopedia

Jet

Sapropel

Red Garnet

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Oil Shale

Peat

Pearl

Lizard Skin Jasper

Sunstone

Petrified Wood (Silicified Wood) (Silicified fossil wood (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified fossil wood (SiO2)

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

Chert (Nodular)

Microcrystalline Silica (SiO2)

Amber (Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O) — mineraloid

Amber

Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O

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

Chert

Chert (Microcrystalline Quartz, SiO2)

Moss Agate (Silicon Dioxide (SiO2) with inclusions) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Natural Pearl (appearing in a jewelry setting) (Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin) — mineral

Natural Pearl (appearing in a jewelry setting)

Calcium Carbonate (mostly Aragonite), CaCO3 with Conchiolin

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

Chert (Black Chert/Flint)

Silicon Dioxide (SiO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

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

Pearl jewelry

Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)

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

Chert (often called Jasper or Flint) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (often called Jasper or Flint)

Microcrystalline Silica (SiO2)

Fossil bivalve shell (Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized) — fossil

Fossil bivalve shell

Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized

Chalcedony (Common Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Common Agate)

Silicon Dioxide (SiO2)

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

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Pearl (Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)) — mineral

Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)

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

Chert (Flint Pebbles)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Chert (SiO2)

Chert (often called Flint) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (often called Flint)

Chert (Cryptocrystalline Silica, SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

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)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert / Flint (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert / Flint

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert (Jasper variety)

Silicon Dioxide (SiO2) with iron oxide impurities

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

Pearl and Garnet Glass (Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass) — mineral and glass

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

mineral and glass

Jasper (Red Jasper) (Silicon Dioxide (SiO₂)) — sedimentary

Jasper (Red Jasper)

Silicon Dioxide (SiO₂)

Chert (often called Flint when found in chalk) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when found in chalk)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Silicon Dioxide (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (often called Flint) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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

Chert

Chert (Microcrystalline Quartz, SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (principally SiO2)) — sedimentary

Petrified Wood

Silicified wood (principally SiO2)

Amber (Succinite (Fossilized Tree Resin)) — gemstone

Amber

Succinite (Fossilized Tree Resin)

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

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Polished amber-colored translucent stone, likely citrine or yellow chalcedony (Most consistent with quartz (SiO₂), potentially citrine; translucent yellow chalcedony is another possibility) — mineral

Polished amber-colored translucent stone, likely citrine or yellow chalcedony

Most consistent with quartz (SiO₂), potentially citrine; translucent yellow chalcedony is another possibility

Chert (Smooth River Pebble) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Green Moss Agate

Silicon Dioxide (SiO2) with Mineral Inclusions

Amber (Succinite (C10H16O)) — mineraloid

Amber

Succinite (C10H16O)