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

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Flint) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Orthoclase Feldspar (Orthoclase (KAlSi3O8)) — mineral

Orthoclase Feldspar

Orthoclase (KAlSi3O8)

Moonstone (Orthoclase Feldspar ((K,Na)AlSi3O8)) — mineral

Moonstone

Orthoclase Feldspar ((K,Na)AlSi3O8)

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

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Garnet (Almandine-Pyrope group, X3Y2(SiO4)3) — mineral

Garnet

Almandine-Pyrope group, X3Y2(SiO4)3

Cat's Eye Chrysoberyl (Chrysoberyl (BeAl2O4)) — mineral

Cat's Eye Chrysoberyl

Chrysoberyl (BeAl2O4)

Turquoise (likely stabilized or simulated Howlite) (CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)) — mineral

Turquoise (likely stabilized or simulated Howlite)

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Chalcedony (Carnelian Agate pebble) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Carnelian Agate pebble)

Silicon Dioxide (SiO2)

Red Jasper (Jasper (Silicate mineral - SiO2)) — sedimentary

Red Jasper

Jasper (Silicate mineral - SiO2)

Red Jasper (Jasper (Silicon Dioxide with Hematite inclusions), SiO2) — sedimentary

Red Jasper

Jasper (Silicon Dioxide with Hematite inclusions), SiO2

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

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Yellow Jasper (Jasper (SiO2) with iron hydroxide inclusions) — sedimentary

Yellow Jasper

Jasper (SiO2) with iron hydroxide inclusions

Moonstone (Orthoclase feldspar (KAlSi3O8)) — mineral

Moonstone

Orthoclase feldspar (KAlSi3O8)

Pearl (Biogenic CaCO3 (Aragonite)) — mineral

Pearl

Biogenic CaCO3 (Aragonite)

Red Jasper (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fuchsite (Chrome Mica) (K(Al,Cr)2(AlSi3O10)(OH)2) — mineral

Fuchsite (Chrome Mica)

K(Al,Cr)2(AlSi3O10)(OH)2

Petrified Wood (Silicified Wood (SiO2-dominant)) — fossil

Petrified Wood

Silicified Wood (SiO2-dominant)

Ironstone Concretion (Limonite/Hematite Nodules) (Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)) — sedimentary

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)

Jasper (Petrified Wood variant) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Jasper (Petrified Wood variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Grey and White Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Grey and White Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Stromatolite (Jasper-replaced) (Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)) — sedimentary

Stromatolite (Jasper-replaced)

Fossilized Stromatolite (Cyanobacteria / Cryptozon / Silica SiO2)

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Quartz Variety)

Microcrystalline Silica (SiO2)

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

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turquoise (possible Dyed Magnesite/Howlite) (CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise (possible Dyed Magnesite/Howlite)

CuAl6(PO4)4(OH)8·4H2O

Blue Tiger's Eye (Crocidolite in Quartz (altered)) — Mineral

Blue Tiger's Eye

Crocidolite in Quartz (altered)

Amethyst (Silicon Dioxide (SiO2) containing iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) containing iron impurities

Amethyst (SiO2 (Silicon Dioxide with Iron impurities)) — mineral

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

Garnet (likely Almandine) (Almandine (Fe3Al2(SiO4)3)) — mineral

Garnet (likely Almandine)

Almandine (Fe3Al2(SiO4)3)

Peridot (Olivine) (Magnesium Iron Silicate (Mg, Fe)2SiO4) — mineral

Peridot (Olivine)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Garnet (Almandine) (Almandine (Fe3Al2(SiO4)3)) — mineral

Garnet (Almandine)

Almandine (Fe3Al2(SiO4)3)

Shale with Vein Infillings (Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.) — Sedimentary Rock

Shale with Vein Infillings

Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.

Sedimentary Rock

Emerald (Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium) — mineral

Emerald

Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium

Carnelian Agate (Carnelian (Silicon Dioxide - SiO2)) — mineral

Carnelian Agate

Carnelian (Silicon Dioxide - SiO2)

Mystic Topaz (Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)) — mineral

Mystic Topaz

Aluminum silicate fluoride hydroxide with titanium coating (Al2SiO4(F,OH)2)

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

Turquoise (CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)) — mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Turquoise (Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O