Rock Identifier

Category

Igneous Rock

Browse igneous rock specimens identified by the Rock Identifier community.

Amethyst (Quartz (SiO2) with trace iron impurities) — Mineral

Amethyst

Quartz (SiO2) with trace iron impurities

Shale or Argillite (Shale (sedimentary) / Argillite (metamorphic)) — Sedimentary or Metamorphic (low-grade)

Shale or Argillite

Shale (sedimentary) / Argillite (metamorphic)

Sedimentary or Metamorphic (low-grade)

Blue Quartz (Quartz (SiO2) with inclusions) — Mineral

Blue Quartz

Quartz (SiO2) with inclusions

Tiger's Iron (Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)) — metamorphic

Tiger's Iron

Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)

White Topaz (Al2SiO4(F,OH)2) — mineral

White Topaz

Al2SiO4(F,OH)2

Sandstone or Limestone (Sedimentary Rock) — Sedimentary

Sandstone or Limestone

Sedimentary Rock

Quartz (Silicon Dioxide (SiO2)) — Mineral

Quartz

Silicon Dioxide (SiO2)

Garnet (likely Almandine or Pyrope) (Garnet Group (e.g., Almandine: Fe3Al2(SiO4)3; Pyrope: Mg3Al2(SiO4)3)) — Mineral

Garnet (likely Almandine or Pyrope)

Garnet Group (e.g., Almandine: Fe3Al2(SiO4)3; Pyrope: Mg3Al2(SiO4)3)

Chert (Iron-Stained) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Iron-Stained)

Microcrystalline Silica (SiO2)

Desert Varnish (on Sandstone) (Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)) — sedimentary

Desert Varnish (on Sandstone)

Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining) (Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)

Quartz Geode (Silicon Dioxide (SiO2) in a Geode body) — sedimentary or igneous (host environment)

Quartz Geode

Silicon Dioxide (SiO2) in a Geode body

sedimentary or igneous (host environment)

Marble (Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.) — Metamorphic Rock

Marble

Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.

Metamorphic Rock

Banded Sandstone (Arenite (with iron oxide banding)) — sedimentary

Banded Sandstone

Arenite (with iron oxide banding)

Sandstone (Wonderstone) (Arenite (composed primarily of SiO2 with Fe2O3 impurities)) — sedimentary

Sandstone (Wonderstone)

Arenite (composed primarily of SiO2 with Fe2O3 impurities)

Sandstone (Banded Sandstone) (Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)) — sedimentary

Sandstone (Banded Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with iron oxide impurities)

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

Quartz (Milky Quartz)

Quartz (SiO2 - Silicon Dioxide)

Note: Item is not a geological specimen (n/a) — none

Note: Item is not a geological specimen

n/a

Note: No specimen visible — N/A

Note: No specimen visible

Wishing Stone with Quartz Veins (Quartzite or Quartz-veined Metamorphic Rock (composed mainly of SiO2)) — metamorphic

Wishing Stone with Quartz Veins

Quartzite or Quartz-veined Metamorphic Rock (composed mainly of SiO2)

Smoky Quartz (SiO2 (Silicon Dioxide)) — Mineral

Smoky Quartz

SiO2 (Silicon Dioxide)

Calcite (Calcite (CaCO₃, Calcium Carbonate)) — Mineral

Calcite

Calcite (CaCO₃, Calcium Carbonate)

Pyrite (Pyrite (FeS2)) — Mineral

Pyrite

Pyrite (FeS2)

Orange Calcite (Calcite (Calcium Carbonate, CaCO3)) — Mineral

Orange Calcite

Calcite (Calcium Carbonate, CaCO3)

Shatter Cone (Impactite (Shatter Cone texture)) — metamorphic

Shatter Cone

Impactite (Shatter Cone texture)

Massive Quartz (Milky or Gray) (Silicon Dioxide (SiO2)) — mineral

Massive Quartz (Milky or Gray)

Silicon Dioxide (SiO2)

Magnetite (Iron Ore) (Magnetite (Fe3O4)) — mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Quartz Geode (with Agate banding) (Silicon Dioxide (SiO2)) — Sedimentary or Igneous (secondary formation)

Quartz Geode (with Agate banding)

Silicon Dioxide (SiO2)

Sedimentary or Igneous (secondary formation)

Fulonite (Fulgurite-like) (Fulgurite (SiO2 fused silica/lechatelierite)) — Metamorphic (Pseudo-igneous)

Fulonite (Fulgurite-like)

Fulgurite (SiO2 fused silica/lechatelierite)

Metamorphic (Pseudo-igneous)

Ferruginous Sandstone (Ironstone Nodules) (Ferruginous Quartz-Arenite (with Goethite/Hematite cement)) — sedimentary

Ferruginous Sandstone (Ironstone Nodules)

Ferruginous Quartz-Arenite (with Goethite/Hematite cement)

Quartz (variety of colors) (SiO2 (Silicon Dioxide)) — Mineral

Quartz (variety of colors)

SiO2 (Silicon Dioxide)

Sandstone (with Iron Staining) (Clastic Sedimentary Rock (primarily Quartz, SiO2)) — sedimentary

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily Quartz, SiO2)

Sodalite (Sodalite - Na8(Al6Si6O24)Cl2) — Mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

Sandstone (Ferruginous) (Arenite (SiO2 with iron oxide impurities)) — sedimentary

Sandstone (Ferruginous)

Arenite (SiO2 with iron oxide impurities)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Silica (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Silica (SiO2)

Chert Breccia (Yellow Jasper) (Silicon Dioxide (SiO2) - Brecciated Chert) — sedimentary

Chert Breccia (Yellow Jasper)

Silicon Dioxide (SiO2) - Brecciated Chert

Bauxite / Iron-rich Laterite (Laterite (principally Al(OH)3, Fe2O3, and SiO2)) — sedimentary

Bauxite / Iron-rich Laterite

Laterite (principally Al(OH)3, Fe2O3, and SiO2)

Sandstone with Quartz Veins (Arenite (primarily SiO2 with Fe2O3 staining)) — sedimentary

Sandstone with Quartz Veins

Arenite (primarily SiO2 with Fe2O3 staining)

Banded Gneiss (Gneiss (pronounced "nice")) — Metamorphic Rock

Banded Gneiss

Gneiss (pronounced "nice")

Metamorphic Rock

Sandstone (specifically Banded Sandstone) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (specifically Banded Sandstone)

Clastic sedimentary rock (primarily SiO2)

Chert Geode or Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Geode or Nodule

Microcrystalline Quartz (SiO2)