Rock Identifier

Category

Rock

Browse rock specimens identified by the Rock Identifier community.

Red Sandstone (Arenite (primarily Quartz with Iron Oxide)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Iron Oxide)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Amygdaloidal Basalt (Amygdaloidal Mafic Volcanic Rock (Basalt)) — igneous

Amygdaloidal Basalt

Amygdaloidal Mafic Volcanic Rock (Basalt)

Obsidian (Volcanic Glass (SiO2)) — igneous

Obsidian

Volcanic Glass (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Banded Agate (specifically Sardonyx Agate) (Silicon Dioxide (SiO2) - Chalcedony variety) — mineral

Banded Agate (specifically Sardonyx Agate)

Silicon Dioxide (SiO2) - Chalcedony variety

Agate (Polished Nodule) (Agate (Silicon Dioxide, SiO2)) — mineral

Agate (Polished Nodule)

Agate (Silicon Dioxide, SiO2)

Caribbean Calcite (Calcium Carbonate with Argonite (CaCO3)) — mineral

Caribbean Calcite

Calcium Carbonate with Argonite (CaCO3)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Carnelian (Carnelian (Chalcedony / SiO2)) — mineral

Carnelian

Carnelian (Chalcedony / SiO2)

Fluorite with Quartz coating (Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)) — mineral

Fluorite with Quartz coating

Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)

Cinnabar in Quartz (Silicon Dioxide (Quartz, SiO2) with Mercury Sulfide inclusions (Cinnabar, HgS)) — mineral

Cinnabar in Quartz

Silicon Dioxide (Quartz, SiO2) with Mercury Sulfide inclusions (Cinnabar, HgS)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Ironstone Concretion (Moqui Marble variety) (Ferruginous Sandstone Concretion) — sedimentary

Ironstone Concretion (Moqui Marble variety)

Ferruginous Sandstone Concretion

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Jasper (Cryptocrystalline Quartz (SiO2)) — sedimentary

Jasper

Cryptocrystalline Quartz (SiO2)

Black Opal (Hydrated silica (SiO2·nH2O)) — mineraloid

Black Opal

Hydrated silica (SiO2·nH2O)

African Turquoise (African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)) — sedimentary

African Turquoise

African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)

Sandstone (Ferruginous) (Arenite with Iron oxide staining (SiO2 with Fe2O3)) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron oxide staining (SiO2 with Fe2O3)

Chert (specifically Flint or Dark Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Dark Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

White Chalcedony (likely Common Opal or Milky Quartz) (Silicon Dioxide (SiO2)) — mineral

White Chalcedony (likely Common Opal or Milky Quartz)

Silicon Dioxide (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Tiffany Stone (Fluorite Opal (a complex mix of Fluorite, Opal, Calcite, Dolomite, Quartz, and Bertrandite)) — mineral

Tiffany Stone

Fluorite Opal (a complex mix of Fluorite, Opal, Calcite, Dolomite, Quartz, and Bertrandite)

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

Quartz with Iron Staining

Silicon Dioxide (SiO2)

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

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Mookaite Jasper (Silicon Dioxide (SiO2) - Radiolarite) — sedimentary

Mookaite Jasper

Silicon Dioxide (SiO2) - Radiolarite

Basalt (Basalt) — igneous

Basalt

Basalt

Chert (concretionary/nodular variant) (Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions) — sedimentary

Chert (concretionary/nodular variant)

Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions

Herkimer Diamond (Quartz Crystal) (Silicon Dioxide (SiO2)) — mineral

Herkimer Diamond (Quartz Crystal)

Silicon Dioxide (SiO2)

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

Chert (Nodular)

Microcrystalline Silica (SiO2)

Quartz with Iron Oxide Monzonite or Sandstone contact (Quartz (SiO2) with Limonite/Hematite staining) — mineral

Quartz with Iron Oxide Monzonite or Sandstone contact

Quartz (SiO2) with Limonite/Hematite staining

Pink Botswana Agate (Silicon Dioxide (SiO₂), a cryptocrystalline variety of Quartz and Chalcedony) — sedimentary

Pink Botswana Agate

Silicon Dioxide (SiO₂), a cryptocrystalline variety of Quartz and Chalcedony

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (varietal: Flint/Jasper mix) (Hydrous Silica (SiO2)) — sedimentary

Chert (varietal: Flint/Jasper mix)

Hydrous Silica (SiO2)

Moss Agate (Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)

Sapphire (Corundum) (Corundum (Al2O3)) — mineral

Sapphire (Corundum)

Corundum (Al2O3)

Pyrite in Matrix (Quartz/Schist) (Iron Sulfide (FeS2)) — mineral

Pyrite in Matrix (Quartz/Schist)

Iron Sulfide (FeS2)

Sandstone (Cross-bedded Drill Core) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Cross-bedded Drill Core)

Clastic Sedimentary Rock (primarily SiO2)

Porphyritic Andesite (Porphyritic Andesite (Intermediate Volcanic Rock)) — igneous

Porphyritic Andesite

Porphyritic Andesite (Intermediate Volcanic Rock)

Basalt (Water-worn Pebble) (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt (Water-worn Pebble)

Basalt (Mafic Extrusive Igneous Rock)