Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)
Porphyritic Basalt (Silica-rich Volcanic Rock)
igneous
Category
Basalt
Browse basalt specimens identified by the Rock Identifier community.
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Scoria
Vesicular Basalt / Scoria (Mafic volcanic rock)
igneous
Greenstone Celt (Polished Stone Axe)
Metamorphosed mafic rock (often Basalt or Diabase)
metamorphic
Moss Agate
Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite
Mineral (variety of Chalcedony)
Agate Geode / Nodular Chalcedony
Silicon Dioxide (SiO2) with impurities
mineral
Sunstone
Plagioclase Feldspar (specifically Oligoclase variety containing hematite or goethite inclusions)", composition: (Ca,Na)(Al,Si)2Si2O8
Mineral
Granite
Granite (composed primarily of Quartz (SiO2), Alkali Feldspar, and Plagioclase)
igneous
Andesite
Andesite (Intermediate Extrusive Igneous Rock)
igneous
Porphyritic Basalt (with Granite inclusion)
Porphyritic Mafic Volcanic Rock
igneous
Scoria
Extrusive Igneous Rock (Basaltic/Andesitic Composition)
igneous
Greenstone
Greenschist (primarily composed of chlorite, actinolite, and epidote)
metamorphic
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Mineral
Carnelian
Silicon dioxide (SiO2) with Iron Oxide impurities (Fe2O3)
mineral
Banded Carnelian Agate
Var. of Chalcedony (SiO2)
mineral
Granite
Intrusive Phaneritic Felsic Igneous Rock
igneous
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
mineral
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Greenschist with Quartz Veining
Greenschist (commonly containing Chlorite, Actinolite, and Epidote)
metamorphic
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
mineral
Biggs Jasper
Cryptocrystalline Quartz (Silicon Dioxide) - SiO2
sedimentary
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of iron)
mineral
Amethyst
Amethyst (Silicon Dioxide - SiO2 with ferric impurities)
mineral
Scoria
Highly vesicular mafic volcanic rock
igneous
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
mineral
Amethyst
Silicon dioxide (SiO2)
mineral
Dyed Purple Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Native Copper
Native Copper (Cu)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst and Peridot
Amethyst (SiO2 with iron impurities) and Peridot ((Mg, Fe)2SiO4)
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
mineral
Blue Chalcedony
Chalcedony (cryptocrystalline Silicon Dioxide - SiO2)
mineral
Druzy Quartz on Milky Quartz
Silicon Dioxide (SiO2)
mineral
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
igneous/sedimentary
Pumice and Scoria
Vesicular Volcanic Ejecta (Rhyolite/Andesite/Basalt)
igneous
Green Moss Agate (Tumbled)
Silicon Dioxide (SiO2) with mineral inclusions
sedimentary
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Amethyst (Faceted)
Silicon Dioxide (SiO2) with iron impurities
mineral
Banded Agate (specifically Lake Superior Agate style)
Agate (Cryptocrystalline Quartz, SiO2)
mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities and natural radiation influence)
mineral