Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Unakite (Unakite (altered granitic rock)) — metamorphic

Unakite

Unakite (altered granitic rock)

Diabase (Dolerite) Cobble (Diabase / Dolerite) — igneous

Diabase (Dolerite) Cobble

Diabase / Dolerite

Granite (Plutonic felsic rock (Quartz, Feldspar, Mica)) — igneous

Granite

Plutonic felsic rock (Quartz, Feldspar, Mica)

Sandstone with Secondary Mineral Encrustation (Arenite with Silica/Calcite deposits (SiO2 or CaCO3)) — sedimentary

Sandstone with Secondary Mineral Encrustation

Arenite with Silica/Calcite deposits (SiO2 or CaCO3)

Granodiorite with Biotite Mica (Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite Mica)) — igneous

Granodiorite with Biotite Mica

Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite Mica)

Gossan with Copper Carbonate (Chrysocolla/Malachite) (Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)) — Mineral/Sedimentary Interface

Gossan with Copper Carbonate (Chrysocolla/Malachite)

Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)

Mineral/Sedimentary Interface

Green Quartzite (Quartzite (primarily SiO2 with chlorite inclusions)) — metamorphic

Green Quartzite

Quartzite (primarily SiO2 with chlorite inclusions)

Chert (Iron-stained River Cobble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained River Cobble)

Microcrystalline Quartz (SiO2)

Granodiorite (Granodiorite (containing Plagioclase, Quartz, and Biotite)) — igneous

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

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

Chert (Chert Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Snowflake Obsidian (Volcanic glass containing Spherulites (SiO2)) — igneous

Snowflake Obsidian

Volcanic glass containing Spherulites (SiO2)

Pebble (river rock/beach pebble) (Pebble (clast size class)) — Sedimentary Rock

Pebble (river rock/beach pebble)

Pebble (clast size class)

Sedimentary Rock

Sandstone (Sandstone (lithified sand)) — sedimentary

Sandstone

Sandstone (lithified sand)

Sandstone (Sandstone (various mineral compositions)) — Sedimentary

Sandstone

Sandstone (various mineral compositions)

Sandstone (Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)) — Sedimentary

Sandstone

Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)

Sandstone (Arenite (SiO2 predominantly)) — sedimentary

Sandstone

Arenite (SiO2 predominantly)

Granite (Granite (felsic intrusive igneous rock)) — igneous

Granite

Granite (felsic intrusive igneous rock)

Crushed Stone (Basalt/Gabbro) (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Crushed Stone (Basalt/Gabbro)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Petrified Wood (Silicified wood (primarily Silicon Dioxide - SiO2)) — mineral (silicate-replaced organic material)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

mineral (silicate-replaced organic material)

Banded Agate Geode (Silicon Dioxide (SiO2)) — mineral

Banded Agate Geode

Silicon Dioxide (SiO2)

Unakite (Epidotized Granite) — metamorphic

Unakite

Epidotized Granite

Blue Lace Agate (Tumbled) (Silicon Dioxide (SiO2)) — mineral

Blue Lace Agate (Tumbled)

Silicon Dioxide (SiO2)

Basalt with Quartz Veins (Basalt (complex silicate) with Quartz (SiO2) intrusions) — igneous

Basalt with Quartz Veins

Basalt (complex silicate) with Quartz (SiO2) intrusions

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Chipped Glass/Plastic Fragment (Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic) — Man-made material (simulant/artifact)

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Man-made material (simulant/artifact)

Fossiliferous Limestone (Fossiliferous Calclutite / Bio-calcarenite (CaCO3)) — sedimentary

Fossiliferous Limestone

Fossiliferous Calclutite / Bio-calcarenite (CaCO3)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2) within a metamorphic matrix) — metamorphic

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within a metamorphic matrix

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

Amethyst

Amethyst (Silicon Dioxide with iron impurities), SiO2

Limestone (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Travertine (Tufa) (Calcium Carbonate (CaCO3)) — sedimentary

Travertine (Tufa)

Calcium Carbonate (CaCO3)

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

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Marble (Recrystallized Carbonate Rock (CaCO3)) — metamorphic

Marble

Recrystallized Carbonate Rock (CaCO3)

Quartz Vein in Host Rock (Silicon Dioxide (SiO2)) — mineral / metamorphic

Quartz Vein in Host Rock

Silicon Dioxide (SiO2)

mineral / metamorphic

Amphibolite (Amphibolite) — metamorphic

Amphibolite

Amphibolite

Granite (Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)) — igneous

Granite

Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)

Pumice (likely) (Pumice (extrusive igneous rock)) — Igneous

Pumice (likely)

Pumice (extrusive igneous rock)

Nuummite (Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)) — metamorphic

Nuummite

Nuummite (Orthoamphibole rock composed of Anthophyllite and Gedrite)

Fossiliferous Limestone (with Coralline Inclusions) (Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (with Coralline Inclusions)

Calcium Carbonate (CaCO3)

Sandstone (likely with Borings or Vesicular Basalt) (Clastic Sedimentary Rock (Sandstone)) — sedimentary

Sandstone (likely with Borings or Vesicular Basalt)

Clastic Sedimentary Rock (Sandstone)

Gneiss (Granitic Gneiss) (Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)) — metamorphic

Gneiss (Granitic Gneiss)

Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)

Mica Schist (Mica Schist (predominantly Muscovite or Biotite sheet silicates)) — metamorphic

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Almandine Garnet in Schist (Almandine, Fe3Al2(SiO4)3) — metamorphic

Almandine Garnet in Schist

Almandine, Fe3Al2(SiO4)3