Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Chert (White Chert/Flint) (Chert (SiO2)) — sedimentary

Chert (White Chert/Flint)

Chert (SiO2)

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

Chert (Quartz)

Microcrystalline Silica (SiO2)

Chert (varieties include Jasper or Flint) (Chert (Microcrystalline Silica, formula: SiO2)) — sedimentary

Chert (varieties include Jasper or Flint)

Chert (Microcrystalline Silica, formula: SiO2)

Chert (Jasper-rich) (Silicon dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Jasper-rich)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Chert (Brecciated River Cobble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Brecciated River Cobble)

Silicon Dioxide (SiO2)

Banded Chert (River Stone/Cobble) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (River Stone/Cobble)

Microcrystalline Quartz (SiO2)

Chert (Quartz Variety) (Chert (mostly SiO2 / Silicon Dioxide)) — sedimentary

Chert (Quartz Variety)

Chert (mostly SiO2 / Silicon Dioxide)

Chert (Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (Pebble)

Microcrystalline silica (SiO2)

Greenstone / Chert (Cryptocrystalline Quartz (SiO2) or Altered Basalt) — sedimentary or metamorphic

Greenstone / Chert

Cryptocrystalline Quartz (SiO2) or Altered Basalt

sedimentary or metamorphic

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone Concretion (Iron-rich Mudstone) (Siderite / Geothite concretion (FeCO3 / FeO(OH))) — sedimentary

Ironstone Concretion (Iron-rich Mudstone)

Siderite / Geothite concretion (FeCO3 / FeO(OH))

Chert (with Quartz veins) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Quartz veins)

Microcrystalline Quartz (SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and Petrified Wood) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Petrified Wood)

Silicon Dioxide (SiO2)

Sandstone (likely Arkose or Quartz Sandstone) (Arenite (SiO2 principal component)) — sedimentary

Sandstone (likely Arkose or Quartz Sandstone)

Arenite (SiO2 principal component)

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

Red Chert (Jasper)

Silicon Dioxide (SiO2)

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

Chert (specifically Banded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (and Flint)

Silicon Dioxide (SiO2)

Fossil Coral (Rugosa or Solitary Coral) (Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)) — sedimentary

Fossil Coral (Rugosa or Solitary Coral)

Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)

Chert (Holey Stone) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Holey Stone)

Microcrystalline Quartz (SiO2)

Amber (Succinite (Carbon-based organic compound; approximate formula C10H16O)) — Mineraloid

Amber

Succinite (Carbon-based organic compound; approximate formula C10H16O)

Ironstone Concretion (Ironstone Gourd) (Limonite/Goethite Concretion (FeOO(H))) — sedimentary

Ironstone Concretion (Ironstone Gourd)

Limonite/Goethite Concretion (FeOO(H))

Pink Opal (Hydrated silicon dioxide (SiO2·nH2O) with inclusions) — mineral

Pink Opal

Hydrated silicon dioxide (SiO2·nH2O) with inclusions

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

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

Shale or Siltstone (Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)) — sedimentary

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)

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

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

Chert (Brecciated Chert)

Silicon Dioxide (SiO2)

Fossilized Sand Tiger Shark Tooth (Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)) — sedimentary (fossil)

Fossilized Sand Tiger Shark Tooth

Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)

sedimentary (fossil)

Dendritic Agate / Moss Agate (Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions) — mineral

Dendritic Agate / Moss Agate

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

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

Green Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

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

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Moss Agate (Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions) — mineral

Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with dendritic inclusions

Shale (Clastic sedimentary rock (primarily clay and silt minerals)) — sedimentary

Shale

Clastic sedimentary rock (primarily clay and silt minerals)

Bituminous Coal (Organic-rich sedimentary rock (Complex hydrocarbons)) — sedimentary

Bituminous Coal

Organic-rich sedimentary rock (Complex hydrocarbons)

Red Amber (Burmite/Cherry Amber) (Succinite / Retinite (Organic Fossilized Resin, C10H16O)) — Mineraloid (Organic)

Red Amber (Burmite/Cherry Amber)

Succinite / Retinite (Organic Fossilized Resin, C10H16O)

Mineraloid (Organic)

Blue Agate (Tumbled and Dyed) (Silicon Dioxide (SiO2) with likely organic dyes) — mineral

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Fossiliferous Limestone (Crinoidal) (Calcite-bearing bioclastic packstone (CaCO3)) — sedimentary

Fossiliferous Limestone (Crinoidal)

Calcite-bearing bioclastic packstone (CaCO3)

Chert (Jasper-like Silicate) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper-like Silicate)

Microcrystalline quartz (SiO2)