Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Category
Browse mineral in igneous rock specimens identified by the Rock Identifier community.
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Hematite
Iron(III) oxide (Fe2O3)
Dalmatian Jasper (Dalmatian Stone)
Perthitic feldspar with Arfvedsonite inclusions
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Citrine
Silicon Dioxide (SiO2)
Pyrite (on Quartz/Host Rock)
Iron Sulfide (FeS₂)
Sapphire (Corundum)
Corundum (Al2O3)
Dalmatian Jasper
Peralkaline rhyolite
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Granite
Granitic intrusive igneous rock
Granite (specifically the Ubatuba variety)
Phaneritic Igneous Rock (Granodiorite/Monzogranite)
Basalt (River Rock/Cobble)
Basalt (no specific mineral formula as it's a rock)
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Mica (Biotite and Muscovite) in Matrix
Potassium aluminum silicate with iron/magnesium (KAl2(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(F,OH)2)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Snowflake Obsidian
Obsidian with Spherulitic Cristobalite (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss (Banded Gneiss)
Gneiss
Granite
Phaneritic intrusive felsic igneous rock
Quartz
Quartz (Silicon Dioxide, SiO2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Obsidian
Obsidian (Volcanic Glass, complex silicate)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
Granite
Granite
Granite
Granite (a felsic intrusive igneous rock)
Granite
Phaneritic intrusive igneous rock (approx. 70 percent SiO2)
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Granodiorite
Granodiorite (Phaneritic intrusive igneous rock containing Plagioclase, Quartz, and Biotite/Amphibole)
Quartz (Microcrystalline/Gravel)
Silicon Dioxide (SiO2)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and Biotite)
Granite
Granite (Felsic Plutonic Rock / SiO2 + Al2O3 + K2O + Na2O + CaO + FeO + MgO)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Lapis Lazuli
Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)