Rock Identifier

Category

Mineral, Specifically A Detrital Grain

Browse mineral, specifically a detrital grain specimens identified by the Rock Identifier community.

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Sandstone (Ferruginous) (Arenite (composed primarily of SiO2 with Fe2O3 cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 cement)

Pegmatitic Granite (Granite (Alkali-feldspar granite) with Quartz and Orthoclase) — igneous

Pegmatitic Granite

Granite (Alkali-feldspar granite) with Quartz and Orthoclase

Sandstone (Micaceous) (Arenite (primarily SiO2 with Phyllosilicates)) — sedimentary

Sandstone (Micaceous)

Arenite (primarily SiO2 with Phyllosilicates)

Conglomerate (Conglomerate (clastic sedimentary rock)) — sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Granite (Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Black Sand (Magnetite Sand) (Magnetite-rich Placers (Fe3O4)) — sedimentary

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)

Blue Quartzite (River Pebble) (Quartzite (primarily SiO2 with Dumortierite or Crocidolite inclusions)) — metamorphic

Blue Quartzite (River Pebble)

Quartzite (primarily SiO2 with Dumortierite or Crocidolite inclusions)

Limestone (specifically Dolomitic Limestone) (Calcium Magnesium Carbonate (CaMg(CO3)2)) — sedimentary

Limestone (specifically Dolomitic Limestone)

Calcium Magnesium Carbonate (CaMg(CO3)2)

Limestone (specifically a Crushed Aggregate fragment) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (specifically a Crushed Aggregate fragment)

Calcium Carbonate (CaCO3)

Chert (specifically a Worked Flint/Knapped Flake) (Chert / Flint (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (specifically a Worked Flint/Knapped Flake)

Chert / Flint (Microcrystalline Quartz, SiO2)

Limestone (specifically Bituminous or Carbonaceous Limestone) (Calcium Carbonate (CaCO3) with Organic Impurities) — sedimentary

Limestone (specifically Bituminous or Carbonaceous Limestone)

Calcium Carbonate (CaCO3) with Organic Impurities

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

Jasper (specifically Oolitic or Brecciated Jasper) (Silicon Dioxide (SiO₂)) — sedimentary

Jasper (specifically Oolitic or Brecciated Jasper)

Silicon Dioxide (SiO₂)

Limestone (specifically Tufa or Travertine) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (specifically Tufa or Travertine)

Calcium Carbonate (CaCO3)

Chert (specifically as a lithic artifact/projectile point) (Chert (Silicon dioxide, SiO2)) — sedimentary

Chert (specifically as a lithic artifact/projectile point)

Chert (Silicon dioxide, SiO2)

Ferruginous Sandstone (Sandstone with Iron Oxide (Limonite/Goethite)) — sedimentary

Ferruginous Sandstone

Sandstone with Iron Oxide (Limonite/Goethite)

Quartz on Sandstone (Silicon Dioxide (SiO2) in Lithic Sandstone) — sedimentary

Quartz on Sandstone

Silicon Dioxide (SiO2) in Lithic Sandstone

Granite Gneiss (Gneiss (High-grade Regional Metamorphic Rock)) — metamorphic

Granite Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Diorite (with Salt-and-Pepper Texture) (Diorite (Intrusive Igneous Rock)) — igneous

Diorite (with Salt-and-Pepper Texture)

Diorite (Intrusive Igneous Rock)

Granite Cobble / Rounded Granite River Rock (Granite) — Igneous

Granite Cobble / Rounded Granite River Rock

Granite

Granite (Granite (Phaneritic Igneous Rock / Quartz, Feldspar, Mica)) — igneous

Granite

Granite (Phaneritic Igneous Rock / Quartz, Feldspar, Mica)

Chert (Grey/Black variety) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Grey/Black variety)

Chert (Silicon Dioxide, SiO2)

Jasper and Yellow Chert (Tumbled) (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper and Yellow Chert (Tumbled)

Microcrystalline Quartz (SiO2)

Fossilized Oyster Shell (Gryphaea or Crassostrea fossil (Calcium Carbonate, CaCO3)) — sedimentary

Fossilized Oyster Shell

Gryphaea or Crassostrea fossil (Calcium Carbonate, CaCO3)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Black Sand (Magnetite Sand) (Magnetite (Fe3O4)) — mineral

Black Sand (Magnetite Sand)

Magnetite (Fe3O4)

Granite (Phaneritic Plutonic Felsic Rock) — igneous

Granite

Phaneritic Plutonic Felsic Rock

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Sandstone (likely Quartzose Sandstone) (Arenite (SiO2 based)) — sedimentary

Sandstone (likely Quartzose Sandstone)

Arenite (SiO2 based)

Rough Gemstone Grains (Mixed Sapphires and Quartz) (Corundum (Al2O3) and Quartz (SiO2)) — mineral

Rough Gemstone Grains (Mixed Sapphires and Quartz)

Corundum (Al2O3) and Quartz (SiO2)

Obsidian (Apache Tear) (Obsidian (Amorphous Volcanic Glass / SiO2 with impurities)) — igneous

Obsidian (Apache Tear)

Obsidian (Amorphous Volcanic Glass / SiO2 with impurities)

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

Sandstone (Quartzose)

Arenite (primarily SiO2)

Chevron Amethyst (Quartz (SiO2) with patterned Amethyst and White Quartz/Milky Quartz) — mineral

Chevron Amethyst

Quartz (SiO2) with patterned Amethyst and White Quartz/Milky Quartz

Orange Calcite (Calcite (CaCO3)) — Mineral

Orange Calcite

Calcite (CaCO3)

Granite (Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)) — igneous

Granite

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Ferruginous Sandstone (Grit) (Clastic Sedimentary (Ironstone-rich Sandstone)) — sedimentary

Ferruginous Sandstone (Grit)

Clastic Sedimentary (Ironstone-rich Sandstone)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Chert (or Flint) (SiO2 (predominantly microcrystalline quartz)) — Sedimentary

Chert (or Flint)

SiO2 (predominantly microcrystalline quartz)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Sandstone (likely Ferruginous) (Arenite (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone (likely Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)