Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic silicate with secondary mineral inclusions)) — Igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic silicate with secondary mineral inclusions)

Olivine in Basalt matrix (Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)) — igneous

Olivine in Basalt matrix

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

Sparkling Druzy Quartz on Matrix (Silicon Dioxide (SiO2) with iron oxide inclusions) — mineral

Sparkling Druzy Quartz on Matrix

Silicon Dioxide (SiO2) with iron oxide inclusions

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

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Grey Chalcedony (Silicon Dioxide (SiO2)) — mineral

Grey Chalcedony

Silicon Dioxide (SiO2)

Vesicular Basalt with Secondary Mineral Infill (Mafic Volcanic Rock (Basalt)) — igneous

Vesicular Basalt with Secondary Mineral Infill

Mafic Volcanic Rock (Basalt)

Greenstone / Greenschist (Chlorite schist / Meta-basalt) — metamorphic

Greenstone / Greenschist

Chlorite schist / Meta-basalt

Porphyry (Porphyritic Basalt or Porphyritic Andesite) — igneous

Porphyry

Porphyritic Basalt or Porphyritic Andesite

Porphyritic Basalt (Chinese Writing Stone) (Porphyritic Basalt or Porphyritic Andesite) — igneous

Porphyritic Basalt (Chinese Writing Stone)

Porphyritic Basalt or Porphyritic Andesite

Greenstone (Chlorite schist / Meta-basalt) — metamorphic

Greenstone

Chlorite schist / Meta-basalt

Basalt with Epidote (Porphyry) (Basalt (with inclusions of Epidote/Feldspar)) — igneous

Basalt with Epidote (Porphyry)

Basalt (with inclusions of Epidote/Feldspar)

Greenstone (Epidote/Chlorite Rich Rock) (Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))) — metamorphic

Greenstone (Epidote/Chlorite Rich Rock)

Metabasalt (often contains Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH))

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

Ruby

Corundum (Al2O3 with Chromium traces)

Prehnite (Prehnite (Ca2Al2Si3O10(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

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

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Amethyst (Amethyst (Silicon Dioxide containing trace Iron impurities, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide containing trace Iron impurities, SiO2)

Opal (Hydrated Silica (SiO2·nH2O)) — mineral

Opal

Hydrated Silica (SiO2·nH2O)

Banded Agate (specifically Lake Superior Agate or similar) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Banded Agate (specifically Lake Superior Agate or similar)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

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

Labradorite

Labradorite (Ca,Na)(Al,Si)4O8

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

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Optical Calcite (Iceland Spar) (Calcium Carbonate (CaCO3)) — mineral

Optical Calcite (Iceland Spar)

Calcium Carbonate (CaCO3)

Greenschist (Greenschist (Chlorite Schist)) — metamorphic

Greenschist

Greenschist (Chlorite Schist)

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

Greenstone

Greenschist (composed of actinolite, chlorite, and epidote)

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

Magnetite / Iron Ore

Magnetite (Fe3O4)

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

Olivine (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4

Basalt River Pebble (Basalt (Mafic volcanic rock)) — igneous

Basalt River Pebble

Basalt (Mafic volcanic rock)

Amygdaloidal Basalt (Vesicular Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)) — igneous

Amygdaloidal Basalt

Vesicular Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)

Basalt River Pebble (Mafic volcanic rock (Basalt)) — igneous

Basalt River Pebble

Mafic volcanic rock (Basalt)

Basalt with Limonite stains (Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)) — igneous

Basalt with Limonite stains

Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)

Basalt River Pebble (Basalt (fine-grained mafic igneous rock)) — igneous

Basalt River Pebble

Basalt (fine-grained mafic igneous rock)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

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

Basalt Cobble

Aphanitic Mafic Igneous Rock (Basalt)

Gabbro (Water-Worn Cobble) (Gabbro) — igneous

Gabbro (Water-Worn Cobble)

Gabbro

Amygdaloidal Basalt (Amygdaloidal Basalt (Mafic Extrusive)) — igneous

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive)

Amygdaloidal Basalt (Basalt with secondary mineral infilling) — igneous

Amygdaloidal Basalt

Basalt with secondary mineral infilling

Porphyritic Basalt (Porphyritic Basalt (with plagioclase phenocrysts)) — igneous

Porphyritic Basalt

Porphyritic Basalt (with plagioclase phenocrysts)

Porphyritic Basalt (Porphyritic Basalt (with plagioclase phenocrysts)) — igneous

Porphyritic Basalt

Porphyritic Basalt (with plagioclase phenocrysts)

Amygdaloidal Basalt (Basalt with Secondary Mineral Infillings) — igneous

Amygdaloidal Basalt

Basalt with Secondary Mineral Infillings

Porphyritic Basalt (Porphyritic Basalt (with Plagioclase phenocrysts)) — igneous

Porphyritic Basalt

Porphyritic Basalt (with Plagioclase phenocrysts)

Basalt (Weathered Pebble) (Extrusive mafic rock (primarily Plagioclase Feldspar and Pyroxene)) — igneous

Basalt (Weathered Pebble)

Extrusive mafic rock (primarily Plagioclase Feldspar and Pyroxene)