Rock Identifier

Category

Mineral, Often A Rock Given Its Aggregate Nature

Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.

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

Black Tourmaline

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

Chert / Flint Nodules in Sandstone (Microcrystalline Quartz (SiO2) within Clastic Sedimentary Rock) — sedimentary

Chert / Flint Nodules in Sandstone

Microcrystalline Quartz (SiO2) within Clastic Sedimentary Rock

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Vesicular Basalt (Lava Rock) (Basalt) — igneous

Vesicular Basalt (Lava Rock)

Basalt

Granite Pebble (Granite (Felsic Intrusive Igneous Rock)) — igneous

Granite Pebble

Granite (Felsic Intrusive Igneous Rock)

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

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

River Stone (likely Siltstone or fine-grained Basalt) (Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)) — sedimentary or igneous

River Stone (likely Siltstone or fine-grained Basalt)

Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)

sedimentary or igneous

Desert Varnish on Sandstone (Ferromanganese coating on Quartz Arenite) — sedimentary

Desert Varnish on Sandstone

Ferromanganese coating on Quartz Arenite

Amethyst (Tumbled) (Quartz (Silicon Dioxide, SiO2) with iron impurities) — mineral

Amethyst (Tumbled)

Quartz (Silicon Dioxide, SiO2) with iron impurities

Scoria (Lava Rock) (Scoria (Mafic Volcanic Rock)) — igneous

Scoria (Lava Rock)

Scoria (Mafic Volcanic Rock)

Black Tourmaline (Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)) — mineral

Black Tourmaline

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)

Sandstone (Banded) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2)

Chert (White/Gray variety) (Chert (SiO2)) — sedimentary

Chert (White/Gray variety)

Chert (SiO2)

Sandstone (Quartzose) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (primarily SiO2)

Chert / Flint (Chert (varieties include Flint)) — Sedimentary

Chert / Flint

Chert (varieties include Flint)

Sandstone (with Iron Staining) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

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

Quartz / Rock Crystal

Silicon Dioxide (SiO2)

Scoria (Lava Rock) (Vesicular Basalt / Scoria) — igneous

Scoria (Lava Rock)

Vesicular Basalt / Scoria

River Rocks (Black) (Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts) — Sedimentary

River Rocks (Black)

Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts

Chert (or Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (or Jasper)

Microcrystalline Quartz (SiO2)

Basalt with Calcite Veins (Aphanitic mafic volcanic rock with CaCO3 inclusions) — igneous

Basalt with Calcite Veins

Aphanitic mafic volcanic rock with CaCO3 inclusions

Chert Nodule (Flint) (Chert (Cryptocrystalline Silica - SiO2)) — sedimentary

Chert Nodule (Flint)

Chert (Cryptocrystalline Silica - SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Basalt with Quartz Veining (Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins) — igneous

Basalt with Quartz Veining

Basalt (Mafic Extrusive Igneous Rock) with SiO2 (Silicon Dioxide) veins

Limonite (Iron Ore) (FeO(OH)·nH2O) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O

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

Fuchsite (Chrome Mica)

Cr-bearing Muscovite - K(Al,Cr)2(AlSi3O10)(OH)2

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Quartz pebble (Silicon Dioxide (SiO2)) — mineral

Quartz pebble

Silicon Dioxide (SiO2)

Basalt with Quartz/Calcite Inclusions (Mafic Volcanic Rock (Fe-Mg silicate rich)) — igneous

Basalt with Quartz/Calcite Inclusions

Mafic Volcanic Rock (Fe-Mg silicate rich)

Chert (Nodule) (Silicon dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (Nodule)

Silicon dioxide (SiO2) - Cryptocrystalline Quartz

Jasper (likely Brecciated or Multi-colored) (Jasper (SiO2)) — sedimentary

Jasper (likely Brecciated or Multi-colored)

Jasper (SiO2)

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Asphalt Concrete (Bituminous Concrete (Anthropic Rock)) — sedimentary

Asphalt Concrete

Bituminous Concrete (Anthropic Rock)

Grey Agate (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Grey Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

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

Quartz (Milky/Common)

Quartz (Silicon Dioxide, SiO2)

Tiger's Eye (Pseudomorph of Crocidolite (SiO2 with iron oxides)) — mineral

Tiger's Eye

Pseudomorph of Crocidolite (SiO2 with iron oxides)

Gold flakes (Native Gold (Au)) — mineral

Gold flakes

Native Gold (Au)

Pumice (Pumice (Vesicular volcanic glass)) — Igneous

Pumice

Pumice (Vesicular volcanic glass)

Chert (specifically tan/pink variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically tan/pink variety)

Silicon Dioxide (SiO2)

Limestone (with Iron-Oxide staining) (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone (with Iron-Oxide staining)

Sedimentary Calcium Carbonate (CaCO3)

Basalt (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt

Basalt (Aphanitic Mafic Igneous Rock)

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)