Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Learn about Organic Gemstone in the encyclopedia

Jet

Jet

Sapropel

Sapropel

Red Garnet

Red Garnet

Bituminous Shale

Bituminous Shale

Black Shale

Black Shale

Petrified Wood

Petrified Wood

Amber

Amber

Peat

Peat

Oil Shale

Oil Shale

Pearl

Pearl

Lizard Skin Jasper

Lizard Skin Jasper

Rhodonite

Rhodonite

Green Sandstone (Glauconitic Sandstone) — sedimentary

Green Sandstone

Glauconitic Sandstone

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

Chert (Flint)

Silicon dioxide (SiO2)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

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

Chert (variant Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Garnet (Polished) (Nesosilicate (Group formula: X3Y2(SiO4)3)) — gemstone

Garnet (Polished)

Nesosilicate (Group formula: X3Y2(SiO4)3)

Faceted Clear Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — gemstone

Faceted Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Amethyst (Silicon dioxide (SiO2)) — mineral

Amethyst

Silicon dioxide (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

River Stone (likely Mudstone or Siltstone) (Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)) — sedimentary

River Stone (likely Mudstone or Siltstone)

Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Fossiliferous Brachiopod in Shale (Brachiopoda (Phylum) preserved in Carbonaceous Shale) — sedimentary

Fossiliferous Brachiopod in Shale

Brachiopoda (Phylum) preserved in Carbonaceous Shale

Cubic Zirconia (Faceted Gemstone) (Zirconium dioxide (ZrO2)) — gemstone

Cubic Zirconia (Faceted Gemstone)

Zirconium dioxide (ZrO2)

Shale with Plant Fossils / Carbonaceous Shale (Laminated Mudrock (Siliciclastic)) — sedimentary

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Dalmatian Stone (commonly Dyed) (Dalmatian Jasper (Peralkaline igneous rock)) — igneous

Dalmatian Stone (commonly Dyed)

Dalmatian Jasper (Peralkaline igneous rock)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Crushed Limestone (Calcite-rich Sedimentary Rock (CaCO3)) — sedimentary

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Chert (with Manganese Oxide coating) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Manganese Oxide coating)

Microcrystalline Quartz (SiO2)

Coquina Limestone (Fossiliferous Limestone) (Calcareous bioclastic sedimentary rock (CaCO3)) — sedimentary

Coquina Limestone (Fossiliferous Limestone)

Calcareous bioclastic sedimentary rock (CaCO3)

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

Chert Pebble (Jasper variant)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert Pebble (Flint) (Microcrystalline/Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert Pebble (Flint)

Microcrystalline/Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified wood (SiO2 - Silicon Dioxide)

Chert (Nodule) (Chert (SiO2)) — sedimentary

Chert (Nodule)

Chert (SiO2)

Chert (Jasper-bearing) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)

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

Yellow Chert (Jasper)

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (varieties: Flint or Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (varieties: Flint or Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (and its variety Flint) (Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz) — sedimentary

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Chert (specifically Chalcedony or Flint variation) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Chalcedony or Flint variation)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz variant, SiO2)) — sedimentary

Petrified Wood

Silicified wood (Quartz variant, SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

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

Chert (Gravel specimen)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert with Druzy Quartz Geode (Microcrystalline Quartz (SiO2)) — sedimentary

Chert with Druzy Quartz Geode

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood) (Silicified Paleoflora (mainly Quartz, SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified Paleoflora (mainly Quartz, SiO2)