Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt) (Porphyritic Basalt (primarily SiO2, Al2O3, FeO, MgO, CaO)) — igneous

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Porphyritic Basalt (primarily SiO2, Al2O3, FeO, MgO, CaO)

Slag (Industrial Glassy Byproduct) (Ferro-silicate Slag) — Anthropogenic / Non-Natural

Slag (Industrial Glassy Byproduct)

Ferro-silicate Slag

Anthropogenic / Non-Natural

Basalt (Water-worn pebble) (Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)) — igneous

Basalt (Water-worn pebble)

Mafic Igneous Rock (primarily Plagioclase feldspar and Pyroxene)

Granodiorite (Phaneritic Plutonic Granodiorite) — igneous

Granodiorite

Phaneritic Plutonic Granodiorite

Granodiorite (Granodiorite (calc-alkaline phaneritic igneous rock)) — igneous

Granodiorite

Granodiorite (calc-alkaline phaneritic igneous rock)

Basalt (Water-worn Pavement Stone) (Basalt (Mafic Extrusive Igneous Rock)) — igneous

Basalt (Water-worn Pavement Stone)

Basalt (Mafic Extrusive Igneous Rock)

Quartzite (river pebble) and Gabbro (crushed rock) (Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)) — Metamorphic and Igneous

Quartzite (river pebble) and Gabbro (crushed rock)

Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)

Metamorphic and Igneous

Basalt (Road Aggregate / Crushed Stone) (Aphanitic Mafic Igneous Rock) — igneous

Basalt (Road Aggregate / Crushed Stone)

Aphanitic Mafic Igneous Rock

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

Amethyst (Druzy Quartz)

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Andesite (Andesite (Intermediate Volcanic Rock)) — igneous

Andesite

Andesite (Intermediate Volcanic Rock)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Blue Chalcedony (Cryptocrystalline Quartz (SiO2)) — mineral

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Chalcedony (Botryoidal/Tumbled Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Botryoidal/Tumbled Agate)

Silicon Dioxide (SiO2)

Agate (Banded Chalcedony (SiO2)) — mineral

Agate

Banded Chalcedony (SiO2)

Bauxite (Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)) — sedimentary

Bauxite

Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)

Banded Agate (Tumbled) (Agate (Variety of Chalcedony/Quartz), SiO2) — mineral

Banded Agate (Tumbled)

Agate (Variety of Chalcedony/Quartz), SiO2

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

Olivine

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

Chalcedony (Yellow Agate) (Cryptocrystalline Quartz (SiO2)) — mineral

Chalcedony (Yellow Agate)

Cryptocrystalline Quartz (SiO2)

Green Chalcedony (likely Chrysoprase or Green Onyx) (Silicon Dioxide (SiO2) with trace nickel or chromium inclusions) — mineral

Green Chalcedony (likely Chrysoprase or Green Onyx)

Silicon Dioxide (SiO2) with trace nickel or chromium inclusions

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

Ruby

Corundum (Al2O3 with Chromium traces)

Carnelian Agate (Silicon Dioxide (SiO2)) — mineral

Carnelian Agate

Silicon Dioxide (SiO2)

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

Peridot

Olivine ((Mg, Fe)2SiO4)

Black Diamond / Black Sapphire (Carbon (C) or Corundum (Al2O3)) — mineral

Black Diamond / Black Sapphire

Carbon (C) or Corundum (Al2O3)

Sunstone (Oligoclase (a variety of Plagioclase Feldspar) - (Na,Ca)(Si,Al)4O8) — mineral

Sunstone

Oligoclase (a variety of Plagioclase Feldspar) - (Na,Ca)(Si,Al)4O8

Green Schist (Greenschist (composed of Chlorite, Actinolite, and Epidote)) — metamorphic

Green Schist

Greenschist (composed of Chlorite, Actinolite, and Epidote)

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

Sunstone

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

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Blue Sapphire (Corundum (Al2O3)) — mineral

Blue Sapphire

Corundum (Al2O3)

Magnetite (Iron Ore) (Magnetite (Fe3O4)) — mineral

Magnetite (Iron Ore)

Magnetite (Fe3O4)

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

Labradorite

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

Greenschist (Chlorite schist) — metamorphic

Greenschist

Chlorite schist

Greenstone (Greenschist / Greenstone (contains epidote, chlorite, and actinolite)) — metamorphic

Greenstone

Greenschist / Greenstone (contains epidote, chlorite, and actinolite)

Quartz Veined Basalt (Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)) — igneous

Quartz Veined Basalt

Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)

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

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Amethyst (Digital/Conceptual Representation) (Amethyst (Silicon Dioxide with iron impurities, SiO2)) — mineral

Amethyst (Digital/Conceptual Representation)

Amethyst (Silicon Dioxide with iron impurities, SiO2)

Orca Agate (Chalcedony) (Silicon Dioxide (SiO2) with inclusions) — mineral

Orca Agate (Chalcedony)

Silicon Dioxide (SiO2) with inclusions

Scoria (Vesicular Basaltic Glass) — igneous

Scoria

Vesicular Basaltic Glass

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Larimar (Blue Pectolite (NaCa2Si3O8(OH))) — mineral

Larimar

Blue Pectolite (NaCa2Si3O8(OH))

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

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Stilbite (Stilbite-Ca (NaCa4Mg[Al9Si27O72]·28H2O)) — mineral

Stilbite

Stilbite-Ca (NaCa4Mg[Al9Si27O72]·28H2O)

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)