Diorite
Phaneritic Intrusive Igneous Rock (Intermediate Composition)
Category
Browse basalt specimens identified by the Rock Identifier community.
Diorite
Phaneritic Intrusive Igneous Rock (Intermediate Composition)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of Fe3+)
Porphyritic Basalt (Chinese Writing Stone/Flower Stone)
Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Scoria (Red Lava Rock)
Scoria
Sunstone
Oligoclase or Andesine (Feldspar Group), (Ca,Na)((Al,Si)4O8)
White Agate / Chalcedony
Silicon Dioxide (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Greenstone / Quartzite Pebble
Metamorphosed Quartz-rich Rock
Scoria (Lava Rock)
Scoria
Amethyst (Rose de France varieties or Amethystine Quartz)
Silicon Dioxide (SiO2) with iron impurities
Sunstone
Oligoclase (Plagioclase Feldspar Group) - (Ca, Na)(Al, Si)4O8
Sunstone (Feldspar)
Plagioclase Feldspar ((Ca, Na)(Al, Si)4O8)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Plagioclase Feldspar (specifically Albite/Oligoclase)
(Na,Ca)(Si,Al)4O8
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4
Olivine (Peridotite)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
Olivine (Peridotite/Dunite)
Olivine (Mg,Fe)2SiO4 within Peridotite
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
Carnelian Agate
Chalcedony (Silicon Dioxide, SiO2) with Iron Oxide impurities
Mahogany Obsidian
Obsidian (volcanic glass with Hematite/Magnetite inclusions)
Amethyst
Silicon Dioxide with trace Iron (SiO2 + Fe3+)
Peridot
Olivine (Mg, Fe)2SiO4
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
Sunstone
Oligoclase (Feldspar variety), (Na,Ca)(Si,Al)4O8
Amethyst
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Carnelian
Carnelian (variety of Chalcedony, SiO2)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Greenschist
Greenschist (comprising Actinolite, Chlorite, and Epidote)
Agate Geode / Thunderegg
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Greenschist (Greenstone)
Greenschist
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Ruby (Pink to Red Corundum)
Al2O3 (Corundum with Chromium impurities)
Scoria (Lava Rock)
Aphanitic vesicular mafic igneous rock
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Blue Lace Agate (Banded Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amethyst (Quartz)
Silicon Dioxide with Iron impurities (SiO2)
Chalcedony
Silicon dioxide (SiO2) - Microcrystalline quartz
Scoria (Lava Rock)
Scoria (Mafic volcanic rock)