Rock Identifier

Category

Organic Gemstone (Not A Rock Or Mineral)

Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.

Petrified Wood (Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)

Petrified Dinosaur Bone (Gembone) (Agatized Dinosaur Bone) — sedimentary

Petrified Dinosaur Bone (Gembone)

Agatized Dinosaur Bone

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Quartz (Quartz (Silicon Dioxide - SiO2)) — Mineral

Quartz

Quartz (Silicon Dioxide - SiO2)

Chert (with Limestone matrix) (Silicon dioxide (SiO2)) — sedimentary

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Peridot (Olivine (Mg, Fe)2SiO4) — mineral

Peridot

Olivine (Mg, Fe)2SiO4

Fossilized Fish Skeleton in Matrix (Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices) — sedimentary

Fossilized Fish Skeleton in Matrix

Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices

Lapis Lazuli (Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)) — metamorphic

Lapis Lazuli

Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)

Green Sandstone (Glauconitic Sandstone) — sedimentary

Green Sandstone

Glauconitic Sandstone

Serpentine (Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4) — metamorphic

Serpentine

Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4

Chert (containing Iron Oxide) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (containing Iron Oxide)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (often called Jasper in this color variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Jasper in this color variety)

Microcrystalline Quartz (SiO2)

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

Chert (Flint/Chalcedony)

Microcrystalline Quartz (SiO2)

Chert / Flint (Microcrystalline or cryptocrystalline quartz (SiO2)) — sedimentary

Chert / Flint

Microcrystalline or cryptocrystalline quartz (SiO2)

Green Aventurine (Green Quartz) (Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)) — Mineral/Metamorphic rock

Green Aventurine (Green Quartz)

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Mineral/Metamorphic rock

Obsidian (Obsidian (volcanic glass), amorphous SiO2 + impurities) — igneous

Obsidian

Obsidian (volcanic glass), amorphous SiO2 + impurities

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)) — mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Chert (specifically Flint or Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (Quartz, SiO2)) — metamorphic

Petrified Wood

Silicified wood (Quartz, SiO2)

Larimar (Pectolite (a blue variety of Pectolite)) — Mineral

Larimar

Pectolite (a blue variety of Pectolite)

Rough Garnet in Matrix (Almandine Garnet (Fe3Al2Si3O12)) — mineral

Rough Garnet in Matrix

Almandine Garnet (Fe3Al2Si3O12)

Chalcedony (Botryoidal or Tumbled) (Chalcedony (SiO₂)) — mineral

Chalcedony (Botryoidal or Tumbled)

Chalcedony (SiO₂)

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

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

Amber (Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)) — mineral

Amber

Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)

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

Chert (Yellow or Ochre Jasper variant)

Microcrystalline Quartz (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Citrine (SiO2 (Silicon Dioxide)) — Mineral

Citrine

SiO2 (Silicon Dioxide)

Prehnite (Prehnite, Ca2Al2Si3O10(OH)2) — Mineral

Prehnite

Prehnite, Ca2Al2Si3O10(OH)2

Sandstone with Secondary Mineral Encrustation (Arenite with Silica/Calcite deposits (SiO2 or CaCO3)) — sedimentary

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Amethyst (Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities) — Mineral

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

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

Chert (Jasper variation)

Silicon Dioxide (SiO2)

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

Precious Opal

Hydrated Silica (SiO2·nH2O)

Brecciated Jasper (Silicon Dioxide (SiO2) with Hematite impurities) — sedimentary

Brecciated Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Glauconitic Sandstone (Glauconitic Quartz Arenite) — sedimentary

Glauconitic Sandstone

Glauconitic Quartz Arenite

Ironstone Concretion (Siderite or Hematite Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite Concretion

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

Amber

Fossilized Tree Resin (Amorphous Hydrocarbon)

Red Sandstone (Sandstone (principally Quartz with Iron Oxide coating)) — sedimentary

Red Sandstone

Sandstone (principally Quartz with Iron Oxide coating)

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

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Amazonite (KAlSi3O8 (Potassium Feldspar, variety of Microcline)) — Mineral

Amazonite

KAlSi3O8 (Potassium Feldspar, variety of Microcline)