Rock Identifier

Category

Organic Structure (Not A Rock)

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

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)

Basalt Pebble with Epidote/Olivine (Vitreous Basalt (SiO2 with Ca/Mg/Fe silicates)) — igneous

Basalt Pebble with Epidote/Olivine

Vitreous Basalt (SiO2 with Ca/Mg/Fe silicates)

Basalt Pebble (Basalt) — igneous

Basalt Pebble

Basalt

Basalt (with possible mineral veining) (Basalt (Aphanitic Mafic Igneous Rock)) — Igneous

Basalt (with possible mineral veining)

Basalt (Aphanitic Mafic Igneous Rock)

Basalt with Vesicular Surface (Basalt (Mafic Extrusive)) — igneous

Basalt with Vesicular Surface

Basalt (Mafic Extrusive)

Chert (Jasper variation) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Basalt River Stone (Basalt) — igneous

Basalt River Stone

Basalt

Banded Agate (specifically Lake Superior Agate) (Silicon dioxide (SiO2) - Cryptocrystalline Chalcedony) — mineral

Banded Agate (specifically Lake Superior Agate)

Silicon dioxide (SiO2) - Cryptocrystalline Chalcedony

Arkosic Sandstone (or Conglomeritic Sandstone fragment) (Arkose (rich in feldspar)) — sedimentary

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Basalt (Vesicular/Scoria) (Vesicular Basalt) — igneous

Basalt (Vesicular/Scoria)

Vesicular Basalt

Basalt (River Pebble) (Basalt (Aphanitic Mafic Volcanic Rock)) — igneous

Basalt (River Pebble)

Basalt (Aphanitic Mafic Volcanic Rock)

Porphyritic Andesite (Porphyritic intermediate volcanic rock (Andesite)) — Igneous

Porphyritic Andesite

Porphyritic intermediate volcanic rock (Andesite)

Basalt (River Stone) (Basalt) — igneous

Basalt (River Stone)

Basalt

Basalt (Drill Core) (Mafic Volcanic Rock (Basalt)) — igneous

Basalt (Drill Core)

Mafic Volcanic Rock (Basalt)

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

Chert (Chalcedony/Agate) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

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

Chert

Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)

Basalt with Scoria/Vesicular Texture (Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Basalt with Scoria/Vesicular Texture

Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)

Basalt with Quartz Veins (Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)) — igneous

Basalt with Quartz Veins

Basalt (composition: SiO2, MgO, FeO, Al2O3, CaO)

Basalt Pebble (Extrusive mafic igneous rock) — igneous

Basalt Pebble

Extrusive mafic igneous rock

Basalt Pebble (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt Pebble

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (River Pebble) (Basalt (Aphanitic Mafic Igneous Rock)) — igneous

Basalt (River Pebble)

Basalt (Aphanitic Mafic Igneous Rock)

Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

Basalt (Vesicular) (Mafic Volcanic Rock (rich in Magnesium and Iron)) — Igneous

Basalt (Vesicular)

Mafic Volcanic Rock (rich in Magnesium and Iron)

Granite Tile (Commercial Granite) (Granite (Phaneritic Quartz-Feldspar Plutonic Rock)) — igneous

Granite Tile (Commercial Granite)

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)

Basalt with Porphyritic Texture (Porphyritic Basalt) — igneous

Basalt with Porphyritic Texture

Porphyritic Basalt

Red Sandstone (Arenite) — sedimentary

Red Sandstone

Arenite

Basalt with Epidote Veins (Mafic Igneous Rock (Basalt)) — igneous

Basalt with Epidote Veins

Mafic Igneous Rock (Basalt)

Basalt River Pebble (Extrusive mafic igneous rock; primarily composed of Plagioclase Feldspar and Pyroxene) — Igneous

Basalt River Pebble

Extrusive mafic igneous rock; primarily composed of Plagioclase Feldspar and Pyroxene

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)

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)