Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Learn about Basalt in the encyclopedia

Basalt

Basalt

Tholeiitic Basalt

Tholeiitic Basalt

Metabasalt

Metabasalt

Variolite

Variolite

Tachylite

Tachylite

Gabbro

Gabbro

Sideromelane

Sideromelane

Palagonite

Palagonite

Diabase

Diabase

Greenstone

Greenstone

Limburgite

Limburgite

Scoria

Scoria

Native Copper (Native Copper (Cu)) — mineral

Native Copper

Native Copper (Cu)

Common Opal in Host Rock (Hydrated Silica (SiO2·nH2O)) — mineraloid

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Sunstone (Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))) — mineral

Sunstone

Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))

Amethyst (Quartz (Silicon Dioxide) with Ferric Iron impurities - SiO2) — mineral

Amethyst

Quartz (Silicon Dioxide) with Ferric Iron impurities - SiO2

Chlorastrolite (Greenstone) (Chlorastrolite (Pumpellyite variety), Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2·H2O) — mineral

Chlorastrolite (Greenstone)

Chlorastrolite (Pumpellyite variety), Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2·H2O

Amethyst (Silicon Dioxide (SiO2) with trace Iron (Fe)) — mineral

Amethyst

Silicon Dioxide (SiO2) with trace Iron (Fe)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Sunstone (Feldspar variety)

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

Blue Sapphire (Corundum (Al2O3)) — mineral

Blue Sapphire

Corundum (Al2O3)

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

Amethyst Geode

Amethyst (Silicon Dioxide, SiO2)

Heat-Treated Citrine (Amethyst Geode Fragment) (Silicon Dioxide (SiO2) with iron impurities) — mineral

Heat-Treated Citrine (Amethyst Geode Fragment)

Silicon Dioxide (SiO2) with iron impurities

Amethyst (Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)) — mineral

Amethyst

Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)

Blue Chalcedony (Cryptocrystalline Quartz (SiO2)) — mineral

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Lake Superior Agate (Agate (Cryptocrystalline variety of Quartz, SiO2)) — mineral

Lake Superior Agate

Agate (Cryptocrystalline variety of Quartz, SiO2)

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

Banded Agate (specifically Lake Superior Agate)

Silicon dioxide (SiO2) - Cryptocrystalline Chalcedony

Carnelian (Carnelian Chalcedony (SiO2)) — mineral

Carnelian

Carnelian Chalcedony (SiO2)

Olivine (often within Peridotite) (Magnesium iron silicate, (Mg,Fe)2SiO4) — mineral

Olivine (often within Peridotite)

Magnesium iron silicate, (Mg,Fe)2SiO4

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

Amethyst

Amethyst (Silicon Dioxide, SiO2)

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

Magnetite (Lodestone variant)

Magnetite (Fe3O4)

Prehnite (Ca2Al(AlSi3O10)(OH)2 (Calcium Aluminum Silicate hydroxide)) — mineral

Prehnite

Ca2Al(AlSi3O10)(OH)2 (Calcium Aluminum Silicate hydroxide)

Greenstone (Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote) — metamorphic

Greenstone

Protolith of basalt, diabase, or gabbro; often contains minerals like chlorite, actinolite, and epidote

Greenstone with Quartz Veining (Epidiorite or Metabasalt with SiO2 (Quartz) veins) — metamorphic

Greenstone with Quartz Veining

Epidiorite or Metabasalt with SiO2 (Quartz) veins

Ruby (Corundum (Al2O3)) — mineral

Ruby

Corundum (Al2O3)

Agate (Lake Superior Agate variant) (Chalcedony / Silicon Dioxide (SiO2)) — sedimentary

Agate (Lake Superior Agate variant)

Chalcedony / Silicon Dioxide (SiO2)

Bauxite (Laterite Clay) (Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))) — sedimentary

Bauxite (Laterite Clay)

Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))

Dyed Blue Agate (Cryptocrystalline Quartz (SiO2)) — mineral

Dyed Blue Agate

Cryptocrystalline Quartz (SiO2)

Epidosite (Epidosite (composed primarily of Epidote and Quartz)) — metamorphic

Epidosite

Epidosite (composed primarily of Epidote and Quartz)

Greenschist (Chlorite Schist) (Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)) — metamorphic

Greenschist (Chlorite Schist)

Greenschist (Metamorphic rock dominated by chlorite, actinolite, and epidote)

Agate (specifically a Thunderegg/Agate Nodule) (Cryptocrystalline Quartz (SiO2)) — mineral

Agate (specifically a Thunderegg/Agate Nodule)

Cryptocrystalline Quartz (SiO2)

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

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Greenstone (Greenschist (metamorphosed mafic igneous rock)) — metamorphic

Greenstone

Greenschist (metamorphosed mafic igneous rock)

Banded Agate (Chalcedony (Silicon Dioxide, SiO2)) — mineral

Banded Agate

Chalcedony (Silicon Dioxide, SiO2)

Labradorite (Labradorite (a calcium-enriched sodic plagioclase feldspar mineral - (Ca, Na)(Al, Si)4O8)) — mineral

Labradorite

Labradorite (a calcium-enriched sodic plagioclase feldspar mineral - (Ca, Na)(Al, Si)4O8)

Carnelian (Carnelian (Silica/Chalcedony, SiO2)) — mineral

Carnelian

Carnelian (Silica/Chalcedony, SiO2)

Amethyst (Silicon Dioxide with trace Iron (SiO2 + Fe3+)) — mineral

Amethyst

Silicon Dioxide with trace Iron (SiO2 + Fe3+)

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

Peridot

Olivine (Mg, Fe)2SiO4

White Chalcedony (likely Common Opal or Milky Quartz) (Silicon Dioxide (SiO2)) — mineral

White Chalcedony (likely Common Opal or Milky Quartz)

Silicon Dioxide (SiO2)

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

Sunstone

Oligoclase (Feldspar variety), (Na,Ca)(Si,Al)4O8

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

Amethyst

Amethyst (Silicon Dioxide with Iron impurities, SiO2)

Quartz Geode (Silicon Dioxide (SiO₂)) — mineral

Quartz Geode

Silicon Dioxide (SiO₂)

Apache Tear (Obsidian (Hydrated Silica Rich Volcanic Glass)) — igneous

Apache Tear

Obsidian (Hydrated Silica Rich Volcanic Glass)

Black Sand (Magnetite Sand) (Magnetite-rich Placers (Fe3O4)) — sedimentary

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)