Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Vesicular Basalt (Amygdaloidal) (Amygdaloidal Basalt (Mafic volcanic rock)) — igneous

Vesicular Basalt (Amygdaloidal)

Amygdaloidal Basalt (Mafic volcanic rock)

Porphyritic Andesite (often called Chinese Writing Stone) (Porphyritic Basaltic Andesite with Feldspar Phenocrysts) — igneous

Porphyritic Andesite (often called Chinese Writing Stone)

Porphyritic Basaltic Andesite with Feldspar Phenocrysts

Olivine in Basalt (Peridotite Xenolith) (Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt) — igneous

Olivine in Basalt (Peridotite Xenolith)

Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt

Labradorite ((Ca, Na)(Al, Si)4O8 (Calcium Sodium Aluminum Silicate)) — mineral

Labradorite

(Ca, Na)(Al, Si)4O8 (Calcium Sodium Aluminum Silicate)

Blue Lace Agate (Silicon Dioxide (SiO₂), a variety of Chalcedony) — mineral

Blue Lace Agate

Silicon Dioxide (SiO₂), a variety of Chalcedony

Greenstone (Greenschist facies) (Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)) — metamorphic

Greenstone (Greenschist facies)

Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)

Labradorite (Labradorite (Plagioclase Feldspar Series: (Ca,Na)(Al,Si)4O8)) — mineral

Labradorite

Labradorite (Plagioclase Feldspar Series: (Ca,Na)(Al,Si)4O8)

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

Sunstone (Plagioclase Feldspar (Na,Ca)(Al,Si)4O8) — mineral

Sunstone

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8

Banded Agate (Onyx type) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Banded Agate (Onyx type)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Amethyst (Silicon dioxide (variant with ferric iron impurities), SiO2) — mineral

Amethyst

Silicon dioxide (variant with ferric iron impurities), SiO2

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

Prehnite

Prehnite, Ca2Al(AlSi3O10)(OH)2

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

Amethyst (Druze)

Silicon Dioxide (SiO2) with iron impurities

Agate Geode (Silicon Dioxide (SiO2)) — mineral

Agate Geode

Silicon Dioxide (SiO2)

Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

Banded Agate (specifically Moss or River Agate variety) (Cryptocrystalline Quartz (SiO2)) — mineral

Banded Agate (specifically Moss or River Agate variety)

Cryptocrystalline Quartz (SiO2)

Epidote with Unakite characteristics ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)) — metamorphic

Epidote with Unakite characteristics

{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Ruby (Corundum (Aluminum Oxide with Chromium), Al2O3:Cr) — mineral

Ruby

Corundum (Aluminum Oxide with Chromium), Al2O3:Cr

Epidote Water-Worn Pebble (Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)) — metamorphic

Epidote Water-Worn Pebble

Epidote {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Greenstone (Greenschist / Greenstone (containing Chlorite, Epidote, Actinolite)) — metamorphic

Greenstone

Greenschist / Greenstone (containing Chlorite, Epidote, Actinolite)

Painted River Pebble (likely Basalt or Greywacke) (Aphanitic Lithic Clast with Anthropogenic Pigment coating) — Sedimentary or Igneous

Painted River Pebble (likely Basalt or Greywacke)

Aphanitic Lithic Clast with Anthropogenic Pigment coating

Sedimentary or Igneous

Magnetite (Lodestone) (Magnetite (Fe3O4)) — mineral

Magnetite (Lodestone)

Magnetite (Fe3O4)

Greenschist (Greenstone) (Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)) — metamorphic

Greenschist (Greenstone)

Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)

Ruby (Pinkish-Red) (Corundum (Al2O3 with Chromium trace)) — mineral

Ruby (Pinkish-Red)

Corundum (Al2O3 with Chromium trace)

Carnelian (Carnelian (Microcrystalline Quartz, SiO2)) — mineral

Carnelian

Carnelian (Microcrystalline Quartz, SiO2)

Pink Sapphire (Corundum (Al2O3) with Chromium/Iron/Titanium trace impurities) — mineral

Pink Sapphire

Corundum (Al2O3) with Chromium/Iron/Titanium trace impurities

Banded Agate (Lace Agate) (Agate (Variety of Cryptocrystalline Quartz), SiO2) — mineral

Banded Agate (Lace Agate)

Agate (Variety of Cryptocrystalline Quartz), SiO2

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

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

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

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Basalt with Quartz/Epidote Vein (Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)) — igneous

Basalt with Quartz/Epidote Vein

Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)

Granite (Granite (Felsic intrusive igneous rock)) — igneous

Granite

Granite (Felsic intrusive igneous rock)

Basalt with Granite Inclusions (Xenoliths) (Mafic igneous rock (Basalt) with Sialic minerals) — igneous

Basalt with Granite Inclusions (Xenoliths)

Mafic igneous rock (Basalt) with Sialic minerals

Granite (Phaneritic Felsic Igneous Rock (Granite)) — igneous

Granite

Phaneritic Felsic Igneous Rock (Granite)

Rhyolite (Rhyolite (High-silica volcanic rock)) — igneous

Rhyolite

Rhyolite (High-silica volcanic rock)

Conglomerate with Native Copper (Clastic Sedimentary Rock with Native Copper (Cu)) — sedimentary

Conglomerate with Native Copper

Clastic Sedimentary Rock with Native Copper (Cu)

Basalt with Quartz/Calcite Veins (Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions) — igneous

Basalt with Quartz/Calcite Veins

Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions

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

Peridot (Olivine)

Olivine, (Mg, Fe)2SiO4

Basalt with Iron Oxidation (Aphanitic Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)) — igneous

Basalt with Iron Oxidation

Aphanitic Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)

Gabbro (Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)) — igneous

Gabbro

Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)

Andesite (Andesite (intermediate volcanic rock)) — igneous

Andesite

Andesite (intermediate volcanic rock)

Peridot in Basalt/Xenolith (Olivine (Mg, Fe)2SiO4 in Vesicular Basalt) — igneous

Peridot in Basalt/Xenolith

Olivine (Mg, Fe)2SiO4 in Vesicular Basalt

Wishing Stone (Basalt or Mudstone with Quartz/Calcite Veins) (Hydrothermally veined Basalt (SiO2/CaCO3 intrusions)) — igneous or sedimentary

Wishing Stone (Basalt or Mudstone with Quartz/Calcite Veins)

Hydrothermally veined Basalt (SiO2/CaCO3 intrusions)

igneous or sedimentary