Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Shale (Fissile mudrock (composed primarily of clay minerals and quartz)) — sedimentary

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

Oak Wood (Wood Grain Pattern) (Quercus (genus)) — Organic (Non-rock)

Oak Wood (Wood Grain Pattern)

Quercus (genus)

Organic (Non-rock)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Moss Agate (Silicon Dioxide with inclusions (SiO2 + Mn/Fe oxides)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Mn/Fe oxides)

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

Pyrite in Shale

Iron Sulfide (FeS2) in Argillaceous Shale

Amber (Succinite (fossilized tree resin)) — mineral

Amber

Succinite (fossilized tree resin)

Amber (Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)) — Organic Mineraloid

Amber

Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)

Organic Mineraloid

Moss Agate (Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite) — Mineral (variety of Chalcedony)

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite

Mineral (variety of Chalcedony)

Shale (with minor calcite veining) (Clastic sedimentary rock (primarily clay minerals and quartz)) — sedimentary

Shale (with minor calcite veining)

Clastic sedimentary rock (primarily clay minerals and quartz)

Amber (Succinite) — mineraloid

Amber

Succinite

Liesegang Ring Siltstone (Siltstone with iron oxide Liesegang bands) — sedimentary

Liesegang Ring Siltstone

Siltstone with iron oxide Liesegang bands

Pearl (Calcium Carbonate (Aragonite) - CaCO3) — mineral

Pearl

Calcium Carbonate (Aragonite) - CaCO3

Coral Fossil (Scleractinia) (Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)) — sedimentary

Coral Fossil (Scleractinia)

Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)

Fossiliferous Limestone (Limestone (CaCO3 - Calcium Carbonate)) — sedimentary

Fossiliferous Limestone

Limestone (CaCO3 - Calcium Carbonate)

Green Moss Agate (Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite) — mineral

Green Moss Agate

Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite

Shale (or Mudstone) (Siltstone/Argillite (composed mainly of clay and silt-sized particles)) — sedimentary

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

Basaltic Tuff / Volcanic Breccia (Pyroclastic Breccia / Lithic Tuff) — igneous

Basaltic Tuff / Volcanic Breccia

Pyroclastic Breccia / Lithic Tuff

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

Pyrite in Shale

Iron Disulfide (FeS2) in Argillaceous Shale

Dendritic Agate (Tree Agate) (Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions) — mineral

Dendritic Agate (Tree Agate)

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

Amber (Succinicum (Succinite); C10H16O) — Mineraloid (Organic)

Amber

Succinicum (Succinite); C10H16O

Mineraloid (Organic)

Tree Agate (or Moss Agate) (Dendritic Agate (Silicon Dioxide - SiO2)) — mineral

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Pink Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Pink Opal

Hydrated Silica (SiO2·nH2O)

Ferruginous Sandstone (Ironstone) (Sedimentary rock with Limonite/Goethite cement) — sedimentary

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Fossil Shell (Bivalve) (Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3) — sedimentary

Fossil Shell (Bivalve)

Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3

Amber (Amber (C10H16O)) — mineral

Amber

Amber (C10H16O)

Amber (Fossilized Tree Resin (Amorphous Hydrocarbon)) — Mineral

Amber

Fossilized Tree Resin (Amorphous Hydrocarbon)

Shale or Slaty Mudstone (Argillaceous sedimentary rock) — sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

Shale (Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)) — sedimentary

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Chert (with Quartz Veining) (Microcrystalline silicon dioxide (SiO2)) — sedimentary

Chert (with Quartz Veining)

Microcrystalline silicon dioxide (SiO2)

Fossil Shark Tooth (Carcharodon or Carcharias fossil (Vertebrate Fossil)) — sedimentary

Fossil Shark Tooth

Carcharodon or Carcharias fossil (Vertebrate Fossil)

Fossiliferous Limestone (CaCO3 (principally Calcite or Aragonite)) — sedimentary

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)

Chert (Beach Pebble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Beach Pebble)

Silicon Dioxide (SiO2)

Chert (Iron-stained) (Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (specifically a weathered Chert nodule or fragment) (Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

River Stone (Chert/Siltstone) (Cryptocrystalline Quartz (SiO2) with trace impurities) — sedimentary

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

Chert (variations include Flint/Jasper) (Chert (SiO2)) — sedimentary

Chert (variations include Flint/Jasper)

Chert (SiO2)

Fossiliferous Limestone (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Chert (specifically Flint or Common Chert) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (specifically Flint or Common Chert)

Chert (Cryptocrystalline Silica, SiO2)