Rock Identifier

Category

Igneous Rock

Browse igneous rock specimens identified by the Rock Identifier community.

Shale (Fissile mudrock (composed of clay-sized particles and detrital grains)) — sedimentary

Shale

Fissile mudrock (composed of clay-sized particles and detrital grains)

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Quartzite River Rock (Quartzite (primarily SiO2)) — metamorphic

Quartzite River Rock

Quartzite (primarily SiO2)

Sandstone or Quartzite (Arenite (if sedimentary) / Quartzite (if metamorphic)) — Sedimentary or Metamorphic

Sandstone or Quartzite

Arenite (if sedimentary) / Quartzite (if metamorphic)

Sedimentary or Metamorphic

Sandstone (Glacial Cobble) (Arenite / Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Glacial Cobble)

Arenite / Sedimentary Rock (primarily SiO2)

Quartz (possibly milky quartz) (Quartz (Silica; SiO₂)) — Mineral

Quartz (possibly milky quartz)

Quartz (Silica; SiO₂)

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Quartzite with Hematite staining (Quartzite (SiO2) with iron oxide inclusions) — metamorphic

Quartzite with Hematite staining

Quartzite (SiO2) with iron oxide inclusions

Quartzite (River Pebble) (Meta-quartzite (composed primarily of SiO2)) — metamorphic

Quartzite (River Pebble)

Meta-quartzite (composed primarily of SiO2)

Yellow Quartzite (River Pebble) (Quartzite (primarily Silicon Dioxide, SiO2)) — metamorphic

Yellow Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide, SiO2)

Quartz Druzy (on Matrix) (Silicon Dioxide (SiO2)) — mineral

Quartz Druzy (on Matrix)

Silicon Dioxide (SiO2)

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

Sandstone (with Iron Staining)

Clastic sedimentary rock (SiO2 with Fe2O3 oxides)

Shale (Fissile mudstone (Shale)) — sedimentary

Shale

Fissile mudstone (Shale)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Sandstone (Ferruginous) (Arenite with Iron Oxide (Limonite/Hematite) coating) — sedimentary

Sandstone (Ferruginous)

Arenite with Iron Oxide (Limonite/Hematite) coating

Banded Gneiss (Variety of Gneiss) (Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)) — Metamorphic Rock

Banded Gneiss (Variety of Gneiss)

Gneiss (specifically, a variety exhibiting prominent banding; mineral composition can vary, but often contains quartz, feldspar, mica, and amphibole)

Metamorphic Rock

Fossiliferous Limestone (Coquina) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Shale (Fissile Siliciclastic Sedimentary Rock) — sedimentary

Shale

Fissile Siliciclastic Sedimentary Rock

Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Agate (specifically a Yellow/Honey Agate) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Agate (specifically a Yellow/Honey Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz (likely) or a Quartzite Pebble (Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.) — Mineral, specifically a detrital grain

Quartz (likely) or a Quartzite Pebble

Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.

Mineral, specifically a detrital grain

Clear Quartz (beads in a bracelet) (Quartz (SiO2)) — Mineral

Clear Quartz (beads in a bracelet)

Quartz (SiO2)

River Stone (likely Basalt or Chert) (Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt) — igneous/sedimentary

River Stone (likely Basalt or Chert)

Silicon Dioxide (SiO2) for chert or Mafic Extrusive Rock for basalt

igneous/sedimentary

Quartz in Matrix (possibly Basalt or Siltstone host) (Silicon Dioxide (SiO2) in Host Rock) — mineral

Quartz in Matrix (possibly Basalt or Siltstone host)

Silicon Dioxide (SiO2) in Host Rock

Orthoclase Feldspar (or K-Feldspar) (Orthoclase (KAlSi3O8)) — Mineral

Orthoclase Feldspar (or K-Feldspar)

Orthoclase (KAlSi3O8)

Quartz-veined Mudstone or Argillite (SiO2 (Quartz) in Siltstone/Mudstone matrix) — sedimentary

Quartz-veined Mudstone or Argillite

SiO2 (Quartz) in Siltstone/Mudstone matrix

Epidote in Quartz (Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)) — Mineral

Epidote in Quartz

Quartz with Epidote inclusions (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH) inclusions)

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

Sandstone

Clastic sedimentary rock (primarily SiO2)

Greywacke (likely) (Greywacke (a type of sandstone)) — Sedimentary

Greywacke (likely)

Greywacke (a type of sandstone)

Lapis Lazuli (Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)) — Mineral

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)

Quartz (Quartz (SiO2)) — Mineral

Quartz

Quartz (SiO2)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Aquamarine and clear quartz (Aquamarine (Be3Al2Si6O18), Quartz (SiO2)) — Mineral

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Sandstone (Sandstone (clastic sedimentary rock)) — Rock

Sandstone

Sandstone (clastic sedimentary rock)

Quartz Vein in Sandstone (Sandstone with Hydrothermal Quartz (SiO2)) — sedimentary

Quartz Vein in Sandstone

Sandstone with Hydrothermal Quartz (SiO2)

Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

Ruby (Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)) — Mineral

Ruby

Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)

Marble (Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).) — Metamorphic Rock

Marble

Marbles are primarily composed of calcite (calcium carbonate, CaCO3) or dolomite (calcium magnesium carbonate, CaMg(CO3)2).

Metamorphic Rock

Botryoidal Chalcedony (Desert Rose / Agate) (Silicon Dioxide (SiO₂)) — Mineral variant

Botryoidal Chalcedony (Desert Rose / Agate)

Silicon Dioxide (SiO₂)

Mineral variant

Banded Slate or Siltstone with Quartz/Calcite Veins (Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)) — metamorphic

Banded Slate or Siltstone with Quartz/Calcite Veins

Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)

Druzy Quartz on Matrix (likely Limestone or Sandstone) (Silicon Dioxide (SiO2) with various trace impurities) — Mineral on Sedimentary Rock

Druzy Quartz on Matrix (likely Limestone or Sandstone)

Silicon Dioxide (SiO2) with various trace impurities

Mineral on Sedimentary Rock

River Pebble (Gravel) (Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)) — sedimentary

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)