Rock Identifier

Category

Organic Gemstone (Not A Rock)

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

Quartz Geode (Citrine or Iron-stained Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz Geode (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

mineral
Turquoise (Turquoise - CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

Turquoise - CuAl6(PO4)4(OH)8·4H2O

mineral
Milky Quartz with Iron Staining (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

mineral
Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

mineral
Agate (Grey Agate Slice) (Microcrystalline Quartz (SiO2)) — mineral

Agate (Grey Agate Slice)

Microcrystalline Quartz (SiO2)

mineral
Rough Ruby (Corundum (Al2O3 with Chromium impurities)) — mineral

Rough Ruby

Corundum (Al2O3 with Chromium impurities)

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

White Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Mineraloid
Coal (specifically Bituminous or Anthracite) (Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N) — sedimentary

Coal (specifically Bituminous or Anthracite)

Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N

sedimentary
Quartz (Druzy or Crystalline variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy or Crystalline variety)

Silicon Dioxide (SiO2)

mineral
Quartz / Rock Crystal (Silicon Dioxide (SiO2)) — mineral

Quartz / Rock Crystal

Silicon Dioxide (SiO2)

mineral
Fossil Coral (Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)) — sedimentary

Fossil Coral

Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)

sedimentary
Yellow Jasper (Jasper, a microcrystalline variety of Quartz (SiO2) with iron inclusions) — sedimentary

Yellow Jasper

Jasper, a microcrystalline variety of Quartz (SiO2) with iron inclusions

sedimentary
Prehnite (Prehnite Ca2Al2Si3O10(OH)2) — mineral

Prehnite

Prehnite Ca2Al2Si3O10(OH)2

mineral
Aquamarine and clear quartz (Aquamarine (Be3Al2Si6O18), Quartz (SiO2)) — Mineral

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Mineral
Quartz (Milk Quartz / Massive Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milk Quartz / Massive Quartz)

Silicon Dioxide (SiO2)

mineral
Clear Quartz (Rock Crystal) (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

mineral
Blue Lace Agate (Chalcedony (a form of Quartz) - SiO2) — Mineral

Blue Lace Agate

Chalcedony (a form of Quartz) - SiO2

Mineral
Clear Quartz (Rock Crystal) (Quartz (Silicon Dioxide, SiO2)) — mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

mineral
Milky and Citrine-type Quartz (Silicon Dioxide (SiO2)) — mineral

Milky and Citrine-type Quartz

Silicon Dioxide (SiO2)

mineral
Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

mineral
Jasper (Jasper (Silica/Quartz) - SiO2) — sedimentary

Jasper

Jasper (Silica/Quartz) - SiO2

sedimentary
Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

mineral
Iolite-bearing Gneiss (Cordierite) (Cordierite (Mg2Al4Si5O18) in Gneiss matrix) — metamorphic

Iolite-bearing Gneiss (Cordierite)

Cordierite (Mg2Al4Si5O18) in Gneiss matrix

metamorphic
Yellow Quartzite (River Pebble) (Quartzite (mainly SiO2)) — metamorphic

Yellow Quartzite (River Pebble)

Quartzite (mainly SiO2)

metamorphic
Amethyst Geode (Amethyst (Silicon Dioxide), Formula: SiO2) — mineral

Amethyst Geode

Amethyst (Silicon Dioxide), Formula: SiO2

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

mineral
Dolomite on Prehnite (Saddle-shaped Dolomite) (Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]) — mineral

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

mineral
Ruby (Corundum (Al2O3) with Chromium traces) — mineral

Ruby

Corundum (Al2O3) with Chromium traces

mineral
Orthoclase Feldspar (Potassium Aluminum Silicate (KAlSi3O8)) — mineral

Orthoclase Feldspar

Potassium Aluminum Silicate (KAlSi3O8)

mineral
Chert (Jasper/Flint variation) (Chert (SiO2)) — sedimentary

Chert (Jasper/Flint variation)

Chert (SiO2)

sedimentary
Almandine Garnet (Almandine (Fe3Al2Si3O12)) — mineral

Almandine Garnet

Almandine (Fe3Al2Si3O12)

mineral
Mahogany Obsidian (Obsidian (Volcanic Glass) with Hematite/Magnetite inclusions) — igneous

Mahogany Obsidian

Obsidian (Volcanic Glass) with Hematite/Magnetite inclusions

igneous
Orange Quartzite (or Aventurine Quartz) (Quartzite (primarily SiO2 with Hematite or Goethite inclusions)) — metamorphic

Orange Quartzite (or Aventurine Quartz)

Quartzite (primarily SiO2 with Hematite or Goethite inclusions)

metamorphic
Carnelian (Carnelian Chalcedony (SiO2 with Iron Oxide impurities)) — mineral

Carnelian

Carnelian Chalcedony (SiO2 with Iron Oxide impurities)

mineral
Quartz (Rose or Clear variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Rose or Clear variety)

Silicon Dioxide (SiO2)

mineral
Asphalt (Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)) — Sedimentary

Asphalt

Asphalt concrete (engineered material, not a naturally occurring rock/mineral in this form)

Sedimentary
Quartz (Milky and Bull Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky and Bull Quartz)

Silicon Dioxide (SiO2)

mineral
Quartz (Quartzite fragment) (Silicon Dioxide (SiO2)) — mineral

Quartz (Quartzite fragment)

Silicon Dioxide (SiO2)

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

Turquoise

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

mineral
Black Tourmaline (Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)) — Mineral

Black Tourmaline

Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Mineral
Diamond (Diamond (pure Carbon, C)) — mineral

Diamond

Diamond (pure Carbon, C)

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

Jasper (Red)

Silicon Dioxide (SiO2)

sedimentary