Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Moss Agate (Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Agate Geode (Banded Chalcedony (Silicon Dioxide, SiO2) with Quartz crystals) — mineral

Agate Geode

Banded Chalcedony (Silicon Dioxide, SiO2) with Quartz crystals

Eye Agate (Sulemani Agate) (Banded Chalcedony (SiO2)) — mineral

Eye Agate (Sulemani Agate)

Banded Chalcedony (SiO2)

Blue Sapphire (Corundum (Al2O3 - Aluminum Oxide)) — mineral

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide)

Peridot (Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)) — mineral

Peridot

Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)

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

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Prehnite (Prehnite - Ca2Al(AlSi3O10)(OH)2) — mineral

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

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

Amethyst

Amethyst (Silicon Dioxide with iron impurities), SiO2

Greenschist (Greenstone River Pebble) (Greenschist (Chlorite Schist)) — metamorphic

Greenschist (Greenstone River Pebble)

Greenschist (Chlorite Schist)

Heat-Treated Citrine (Amethyst Cathedral with Agate inclusions) (Silicon Dioxide (SiO2) with iron impurities) — mineral

Heat-Treated Citrine (Amethyst Cathedral with Agate inclusions)

Silicon Dioxide (SiO2) with iron impurities

Banded Agate with Druzy Quartz (Agate (Silicon Dioxide - SiO2)) — mineral

Banded Agate with Druzy Quartz

Agate (Silicon Dioxide - SiO2)

Schist (Mica Schist (Variable chemistry, often rich in muscovite and biotite)) — metamorphic

Schist

Mica Schist (Variable chemistry, often rich in muscovite and biotite)

Lake Superior Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Lake Superior Agate

Cryptocrystalline Quartz (SiO2)

Amethyst Lace Agate / Banded Amethyst (Silicon Dioxide (SiO2) with Fe3+ impurities) — mineral

Amethyst Lace Agate / Banded Amethyst

Silicon Dioxide (SiO2) with Fe3+ impurities

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

Amethyst Geode

Silicon Dioxide (SiO2) with iron impurities

Peridot (Olivine ((Mg, Fe)2SiO4)) — mineral

Peridot

Olivine ((Mg, Fe)2SiO4)

Scoria (Lava Rock) (Scoria (Vesicular Basaltic Glass/Rock)) — igneous

Scoria (Lava Rock)

Scoria (Vesicular Basaltic Glass/Rock)

Amethyst (Quartz variety; SiO2 (Silicon Dioxide)) — Mineral

Amethyst

Quartz variety; SiO2 (Silicon Dioxide)

Greenstone (Greenschist (primarily composed of chlorite, actinolite, and epidote)) — metamorphic

Greenstone

Greenschist (primarily composed of chlorite, actinolite, and epidote)

Carnelian (Silicon dioxide (SiO2) with Iron Oxide impurities (Fe2O3)) — mineral

Carnelian

Silicon dioxide (SiO2) with Iron Oxide impurities (Fe2O3)

Banded Carnelian Agate (Var. of Chalcedony (SiO2)) — mineral

Banded Carnelian Agate

Var. of Chalcedony (SiO2)

Granite (Granite (composed primarily of Quartz (SiO2), Alkali Feldspar, and Plagioclase)) — igneous

Granite

Granite (composed primarily of Quartz (SiO2), Alkali Feldspar, and Plagioclase)

Andesite (Andesite (Intermediate Extrusive Igneous Rock)) — igneous

Andesite

Andesite (Intermediate Extrusive Igneous Rock)

Sunstone (Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8) — Mineral

Sunstone

Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8

Granite (Intrusive Phaneritic Felsic Igneous Rock) — igneous

Granite

Intrusive Phaneritic Felsic Igneous Rock

Granite (Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)) — igneous

Granite

Phaneritic Plutonic Igneous Rock (primarily composed of quartz, alkali feldspar, and plagioclase)

Chalcedony (Desert Rose or Botryoidal Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Desert Rose or Botryoidal Chalcedony)

Silicon Dioxide (SiO2)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Peridotite (Olivine/Peridot) (Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)) — igneous

Peridotite (Olivine/Peridot)

Peridotite: (Mg,Fe)2SiO4 (Olivine-rich ultramafic rock)

Wishing Stone (Basalt/Greywacke with Quartz Vein) (Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion) — igneous/sedimentary

Wishing Stone (Basalt/Greywacke with Quartz Vein)

Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion

igneous/sedimentary

Black Sapphire (Basaltic Blue Sapphire) (Corundum (Al2O3)) — mineral

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Ruby (Corundum (Al2O3 with Chromium traces)) — mineral

Ruby

Corundum (Al2O3 with Chromium traces)

Greenschist with Quartz Veining (Greenschist (commonly containing Chlorite, Actinolite, and Epidote)) — metamorphic

Greenschist with Quartz Veining

Greenschist (commonly containing Chlorite, Actinolite, and Epidote)

Magnetite (Magnetite (Iron(II,III) oxide, Fe3O4)) — mineral

Magnetite

Magnetite (Iron(II,III) oxide, Fe3O4)

Biggs Jasper (Cryptocrystalline Quartz (Silicon Dioxide) - SiO2) — sedimentary

Biggs Jasper

Cryptocrystalline Quartz (Silicon Dioxide) - SiO2

Amethyst (Amethyst (Silicon Dioxide - SiO2 with impurities of iron)) — mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with impurities of iron)

Amethyst (Amethyst (Silicon Dioxide - SiO2 with ferric impurities)) — mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with ferric impurities)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Scoria (Vesicular Basaltic Glass (comprised primarily of volcanic glass/silica with plagioclase, pyroxene, and olivine crystals)) — igneous

Scoria

Vesicular Basaltic Glass (comprised primarily of volcanic glass/silica with plagioclase, pyroxene, and olivine crystals)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Amethyst Cluster (Amethyst (Silicon Dioxide), chemical formula: SiO2) — mineral

Amethyst Cluster

Amethyst (Silicon Dioxide), chemical formula: SiO2

Scoria (Lava Rock) (Scoria) — igneous

Scoria (Lava Rock)

Scoria