Rock Identifier

Category

Organic (Geological Relative)

Browse organic (geological relative) specimens identified by the Rock Identifier community.

Black Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities) — igneous

Black Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities

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)

Green Schist (Greenschist) (Greenschist facies metamorphic rock) — metamorphic

Green Schist (Greenschist)

Greenschist facies metamorphic rock

Greisen (Quartz-Muscovite-Turretine Rock) (Greisen) — Metamorphic Rock

Greisen (Quartz-Muscovite-Turretine Rock)

Greisen

Metamorphic Rock

Slate (Foliated Metamorphic Rock (composed mainly of Quartz, Illite, and Chlorite)) — metamorphic

Slate

Foliated Metamorphic Rock (composed mainly of Quartz, Illite, and Chlorite)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Pumice (Vesicular volcanic glass) — igneous

Pumice

Vesicular volcanic glass

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Snowflake Obsidian (Volcanic Glass (SiO2 + impurities)) — igneous

Snowflake Obsidian

Volcanic Glass (SiO2 + impurities)

Carnelian (Silicon Dioxide (SiO2) - variety of Chalcedony) — mineral

Carnelian

Silicon Dioxide (SiO2) - variety of Chalcedony

Milky Quartz (Quartz (Silica / Silicon Dioxide, SiO2)) — mineral

Milky Quartz

Quartz (Silica / Silicon Dioxide, SiO2)

Obsidian (Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)) — igneous

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

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

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx') (Calcite (Calcium Carbonate, CaCO3)) — Sedimentary

Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')

Calcite (Calcium Carbonate, CaCO3)

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

Clear/White Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Rounded pale quartz-rich pebble (Likely milky quartz or quartzite (SiO₂); exact identification is uncertain from the photograph) — mineral

Rounded pale quartz-rich pebble

Likely milky quartz or quartzite (SiO₂); exact identification is uncertain from the photograph

Carnelian (Silicon Dioxide (Chalcedony variety), SiO2) — gemstone

Carnelian

Silicon Dioxide (Chalcedony variety), SiO2

Calcite crystal cluster (dogtooth/saddle calcite) (Calcite — calcium carbonate, CaCO₃) — mineral

Calcite crystal cluster (dogtooth/saddle calcite)

Calcite — calcium carbonate, CaCO₃

Obsidian (Volcanic Glass (Amorphous Silica)) — igneous

Obsidian

Volcanic Glass (Amorphous Silica)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Obsidian (Obsidian (Volcanic Glass; SiO2 content > 70%)) — igneous

Obsidian

Obsidian (Volcanic Glass; SiO2 content > 70%)

Obsidian (Obsidian (Volcanic glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic glass, primarily SiO2)

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

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Granite (Granite (a plutonic igneous rock)) — Igneous

Granite

Granite (a plutonic igneous rock)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Asphalt (Aggregate) (Bituminous macadam / Concrete Aggregate) — sedimentary

Asphalt (Aggregate)

Bituminous macadam / Concrete Aggregate

Slate (Foliated low-grade metamorphic rock) — metamorphic

Slate

Foliated low-grade metamorphic rock

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

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Greenschist (Chlorite Schist) (Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)) — metamorphic

Greenschist (Chlorite Schist)

Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)

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

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

Agate (Chalcedony (SiO2)) — mineral

Agate

Chalcedony (SiO2)

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

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Jade (Nephrite or Jadeite) (Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2 - a variety of actinolite, an amphibole mineral); Jadeite (Na(Al,Fe3+)Si2O6 - a pyroxene mineral)) — Metamorphic rock (for both Nephrite and Jadeite)

Jade (Nephrite or Jadeite)

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2 - a variety of actinolite, an amphibole mineral); Jadeite (Na(Al,Fe3+)Si2O6 - a pyroxene mineral)

Metamorphic rock (for both Nephrite and Jadeite)

Obsidian (Obsidian (volcanic glass), predominantly amorphous SiO₂) — Igneous

Obsidian

Obsidian (volcanic glass), predominantly amorphous SiO₂

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Slate (Foliated Metamorphic Rock (composed mainly of clay minerals or micas)) — metamorphic

Slate

Foliated Metamorphic Rock (composed mainly of clay minerals or micas)

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

Milky Quartz

Quartz / Silicon Dioxide (SiO2)

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

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite/Magnetite inclusions)