Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Category
Browse mineral on igneous rock specimens identified by the Rock Identifier community.
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Dalmatian Jasper (Dalmatian Stone)
Perthitic feldspar with Arfvedsonite inclusions
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Kimberlite
Kimberlite
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Sapphire (Corundum)
Corundum (Al2O3)
Citrine
Silicon Dioxide (SiO2)
Granite (specifically the Ubatuba variety)
Phaneritic Igneous Rock (Granodiorite/Monzogranite)
Granite
Granite (a felsic intrusive igneous rock)
Granite
Granite (a phaneritic intrusive igneous rock)
Clear Quartz (Druzy/Crystal Cluster)
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Black Tourmaline (Schorl)
Schorl (Sodium iron silicate hydroxide boron silicate); NaFe3Al6(BO3)3Si6O18(OH)4
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)
Diorite (Polished River Pebble)
Diorite (Intermediate intrusive igneous rock)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Jasper in Basalt Matrix
Silicon Dioxide (SiO2) with impurities; Chalcedony
Dalmatian Jasper
Peralkaline rhyolite
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Ferruginous Quartz Cobble
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Mica (Biotite and Muscovite) in Matrix
Potassium aluminum silicate with iron/magnesium (KAl2(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(F,OH)2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
Granite
Granite (Felsic Plutonic Rock / SiO2 + Al2O3 + K2O + Na2O + CaO + FeO + MgO)
Basalt (River Rock/Cobble)
Basalt (no specific mineral formula as it's a rock)
Clear Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Diabase (Dolerite) Cobble
Diabase / Dolerite
Obsidian
Volcanic Glass (Amorphous Silica)
Quartz (Milk Quartz / Massive Quartz)
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Biotite (Black Mica)
Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2
Gneiss
Foliated Metamorphic Rock (Gneiss)
Granite
Granite (Phaneritic intrusive igneous rock)
Granite Gneiss
Gneiss (High-grade Metamorphic Rock)
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase)