Rock Identifier

Category

Organic Structure (Not A Rock)

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

Basalt (Basalt (Volcanic Mafic Rock)) — igneous

Basalt

Basalt (Volcanic Mafic Rock)

Granite (Granite) — igneous

Granite

Granite

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Desert Rose (Gypsum (variety Selenite) or Barite, CaSO4·2H2O) — mineral

Desert Rose

Gypsum (variety Selenite) or Barite, CaSO4·2H2O

Sandstone (Picture Sandstone) (Sandstone (primarily Quartz with Iron Oxide impurities)) — sedimentary

Sandstone (Picture Sandstone)

Sandstone (primarily Quartz with Iron Oxide impurities)

Serpentinite (Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)

Granite (Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)) — igneous

Granite

Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Chert (Jasper/Mudstone variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Mudstone variant)

Silicon Dioxide (SiO2)

Sandstone (with Iron Siderite Concretion) (Arenite with Ironstone Concretion (FeCO3)) — sedimentary

Sandstone (with Iron Siderite Concretion)

Arenite with Ironstone Concretion (FeCO3)

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)

Basalt Pebble (Aphanitic mafic volcanic rock) — igneous

Basalt Pebble

Aphanitic mafic volcanic rock

Unakite (Unakite (metasomatized granite)) — metamorphic

Unakite

Unakite (metasomatized granite)

Pumice (Pumice (a highly vesicular extrusive igneous rock)) — igneous

Pumice

Pumice (a highly vesicular extrusive igneous rock)

Andesite (Andesite (contains Plagioclase feldspar, Pyroxene, Hornblende)) — igneous

Andesite

Andesite (contains Plagioclase feldspar, Pyroxene, Hornblende)

Serpentinite (Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4) — metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Sandstone (Ferruginous Concretion) (Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement) — sedimentary

Sandstone (Ferruginous Concretion)

Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement

Copper-bearing Quartz (likely Chrysocolla or Malachite staining) (Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock) — mineral

Copper-bearing Quartz (likely Chrysocolla or Malachite staining)

Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock

Chert (specifically Gray Chert) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Gray Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Wishing Stone (Gneiss or Basalt with Quartz Vein) (Gneiss or Metabasalt (with a Quartz or Calcite intrusion)) — metamorphic

Wishing Stone (Gneiss or Basalt with Quartz Vein)

Gneiss or Metabasalt (with a Quartz or Calcite intrusion)

Chert (Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)) — Sedimentary

Chert

Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)

Granite (Granite (Phaneritic Igneous Rock)) — igneous

Granite

Granite (Phaneritic Igneous Rock)

Serpentine (Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4) — metamorphic

Serpentine

Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4

Quartz in Basalt (Xenocryst) (Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock) — Igneous

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Serpentine (Serpentinite) (Antigorite, Lizardite, or Chrysotile; (Mg,Fe)3Si2O5(OH)4) — metamorphic

Serpentine (Serpentinite)

Antigorite, Lizardite, or Chrysotile; (Mg,Fe)3Si2O5(OH)4

Thunderegg (Agate-filled Rhyolitic Nodule (SiO2)) — mineral

Thunderegg

Agate-filled Rhyolitic Nodule (SiO2)

Red Sandstone (Arenite (with Iron Oxide)) — sedimentary

Red Sandstone

Arenite (with Iron Oxide)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Sandstone (likely Iron-rich or Arkosic) (Arenite (SiO2 with FeO(OH) or Fe2O3 staining)) — sedimentary

Sandstone (likely Iron-rich or Arkosic)

Arenite (SiO2 with FeO(OH) or Fe2O3 staining)

Unakite (Unakite (Episyenite composition: Feldspar, Epidote, and Quartz)) — metamorphic

Unakite

Unakite (Episyenite composition: Feldspar, Epidote, and Quartz)

Red Quartzite (Ferruginous Quartz) (Quartzite (SiO2 with Fe2O3 inclusions)) — metamorphic

Red Quartzite (Ferruginous Quartz)

Quartzite (SiO2 with Fe2O3 inclusions)

Amethyst (Chevron Amethyst) (Amethystine Quartz (SiO2)) — mineral

Amethyst (Chevron Amethyst)

Amethystine Quartz (SiO2)

White Quartz (Tumbled) (Silicon Dioxide (SiO2)) — mineral

White Quartz (Tumbled)

Silicon Dioxide (SiO2)

Granodiorite (Riverbed Cobble) (Granodiorite) — igneous

Granodiorite (Riverbed Cobble)

Granodiorite

Gneiss (with Quartzite and Biotite) (Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)) — metamorphic

Gneiss (with Quartzite and Biotite)

Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)

Milky Quartz Pebble (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Pink Granite (Granite (Phaneritic igneous rock)) — igneous

Pink Granite

Granite (Phaneritic igneous rock)

Garnetiferous Pegmatite (Pegmatite with Almandine Garnet and Muscovite) — igneous

Garnetiferous Pegmatite

Pegmatite with Almandine Garnet and Muscovite

Granodiorite (Granodiorite) — igneous

Granodiorite

Granodiorite

Unakite (Unakite Epidosite (Granite with epidote and orthoclase)) — metamorphic

Unakite

Unakite Epidosite (Granite with epidote and orthoclase)

Carnelian (Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)