Rock Identifier

Category

Basalt

Browse basalt specimens identified by the Rock Identifier community.

Amethyst (Silicon dioxide (SiO2)) — mineral

Amethyst

Silicon dioxide (SiO2)

Black Onyx (Black Chalcedony (SiO2)) — mineral

Black Onyx

Black Chalcedony (SiO2)

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

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Moss Agate / Carnelian Agate (Silicon Dioxide (SiO2) with iron and manganese inclusions) — mineral

Moss Agate / Carnelian Agate

Silicon Dioxide (SiO2) with iron and manganese inclusions

Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Bloodstone (also known as Heliotrope) (Silicon Dioxide (SiO2) - variety of Chalcedony) — mineral

Bloodstone (also known as Heliotrope)

Silicon Dioxide (SiO2) - variety of Chalcedony

Dyed Agate (Silicon Dioxide (SiO2) - variety Chalcedony) — mineral

Dyed Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Agate (specifically Carnelian Agate or Sardagate) (Silicon dioxide (SiO2) - variety of chalcedony) — mineral

Agate (specifically Carnelian Agate or Sardagate)

Silicon dioxide (SiO2) - variety of chalcedony

Moss Agate (Chalcedony (Silicon Dioxide with inclusions) - SiO2) — mineral

Moss Agate

Chalcedony (Silicon Dioxide with inclusions) - SiO2

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

Carnelian Agate

Silicon Dioxide (SiO2) - Carnelian variety of Chalcedony

Scoria (Lava Rock) (Scoria (extrusive volcanic rock)) — igneous

Scoria (Lava Rock)

Scoria (extrusive volcanic rock)

Yellow Chalcedony (Agate) (Silicon Dioxide (SiO2)) — mineral

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Obsidian (Volcanic glass (SiO2 - Silicon Dioxide with impurities)) — igneous

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Blue Agate (Chalcedony (SiO2)) — mineral

Blue Agate

Chalcedony (SiO2)

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

Peridot

Olivine (Mg,Fe)2SiO4

Blue Chalcedony Geode (with Quartz Druzy) (Silicon Dioxide (SiO2) - Microcrystalline variety of Quartz) — mineral

Blue Chalcedony Geode (with Quartz Druzy)

Silicon Dioxide (SiO2) - Microcrystalline variety of Quartz

Ventifact (Eolian Ventifact (often composed of basalt, chert, or quartzite)) — sedimentary

Ventifact

Eolian Ventifact (often composed of basalt, chert, or quartzite)

Porphyry (Porphyritic Igneous Rock (likely Porphyritic Andesite or Basalt)) — igneous

Porphyry

Porphyritic Igneous Rock (likely Porphyritic Andesite or Basalt)

Amethyst (SiO2 (Silicon Dioxide)) — Mineral

Amethyst

SiO2 (Silicon Dioxide)

Red Garnet (Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)) — Mineral

Red Garnet

Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)

Dragon Blood Jasper (Epidote with Red Jasper inclusions (SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))) — metamorphic

Dragon Blood Jasper

Epidote with Red Jasper inclusions (SiO2 and Ca2(Al,Fe)3(SiO4)3(OH))

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

Peridot

Olivine ((Mg, Fe)2SiO4)

Amethyst Geode (Carved) (Amethyst (Violet Crystalline Quartz - SiO2)) — mineral

Amethyst Geode (Carved)

Amethyst (Violet Crystalline Quartz - SiO2)

Sunstone (Oligoclase (Plagioclase Feldspar) with inclusions - (Ca, Na)((Al, Si)4O8)) — mineral

Sunstone

Oligoclase (Plagioclase Feldspar) with inclusions - (Ca, Na)((Al, Si)4O8)

Carnelian Agate (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

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

Amethyst

Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)

Amethyst (SiO2 (Silicon Dioxide)) — mineral

Amethyst

SiO2 (Silicon Dioxide)

Larimar (Pectolite [NaCa2Si3O8(OH)] with copper substitution) — mineral

Larimar

Pectolite [NaCa2Si3O8(OH)] with copper substitution

Chalcedony (Agate) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — mineral

Chalcedony (Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Sunstone

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

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

Amethyst (Tumbled)

Silicon Dioxide (SiO2) with iron impurities

Amethyst (Amethyst (SiO2 with Iron impurities)) — mineral

Amethyst

Amethyst (SiO2 with Iron impurities)

Scoria (Lava Rock) (Scoria (highly vesicular extrusive igneous rock)) — igneous

Scoria (Lava Rock)

Scoria (highly vesicular extrusive igneous rock)

Obsidian (Obsidian (Volcanic Glass, SiO2 + impurities)) — igneous

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Amethyst (Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities

Dolomite on Prehnite (Saddle-shaped Dolomite) (Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]) — mineral

Dolomite on Prehnite (Saddle-shaped Dolomite)

Dolomite [CaMg(CO3)2] on Prehnite [Ca2Al(AlSi3O10)(OH)2]

Olivine (likely Peridot variety) (Olivine Mineral Group (specifically Forsterite-Fayalite solid solution series); Chemical formula: (Mg,Fe)2SiO4) — Mineral

Olivine (likely Peridot variety)

Olivine Mineral Group (specifically Forsterite-Fayalite solid solution series); Chemical formula: (Mg,Fe)2SiO4

Green Apophyllite and Stilbite on Quartz Cluster (Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)) — Mineral

Green Apophyllite and Stilbite on Quartz Cluster

Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)

Quartz Druze on Matrix (Silicon Dioxide (SiO2)) — mineral

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Agate (Dyed High-Grade Polished Slice) (Silicon dioxide (SiO2), Chalcedony crystal variety) — mineral

Agate (Dyed High-Grade Polished Slice)

Silicon dioxide (SiO2), Chalcedony crystal variety

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Stream Pebble (Basalt/Greywacke) (Mafic Igneous Rock (Fine-grained)) — igneous

Stream Pebble (Basalt/Greywacke)

Mafic Igneous Rock (Fine-grained)