Sapphire
Corundum (Al2O3)
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Sapphire
Corundum (Al2O3)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky Quartz vein fragment)
Silicon Dioxide (SiO2)
Greenstone
Metamorphosed Mafic Igneous Rock
Blue Glass or Slag Glass
Amorphous Silica (Anthropogenic Glass)
White Quartzite
Quartzite (primarily SiO2 - Silicon Dioxide)
Diorite
Diorite (plutonic igneous rock)
Milky Quartz
Silicon Dioxide (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
Milky Quartz with Iron Oxide Weathering
Silicon Dioxide (SiO2) with Goethite/Limonite coatings
Gneiss
Gneiss
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Diorite
Diorite (Intermediate intrusive igneous rock)
Dioptase
Dioptase (CuSiO3 · H2O)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Dragonstone (Brecciated Basalt/Diabase with Epidote and Quartz)
Brecciated mafic igneous rock
Silicon Carbide (Carborundum)
Silicon Carbide (SiC)
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
Asphalt (Aggregate)
Bituminous macadam / Concrete Aggregate
Quartz Drusy on Matrix
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Quartz
Quartz (SiO2)
Granodiorite
Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)
Iron-rich slag or limonite-bearing rock
Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O); possibly industrial iron slag
Quartz Vein
Silicon Dioxide (SiO2)
Pyrite with Iron Oxides (Fool's Gold in Matrix)
Iron Sulfide (FeS2)
Greenstone
Metabasalt / Metamorphosed Igneous Rock
Blue Sapphire
Corundum (Al2O3 with iron and titanium trace elements)
Granite
Phaneritic Igneous Rock (Granite)
Basalt with Epidote/Quartz Vein
Mafic Volcanic Rock with Hydrothermal Veining
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
Milky Quartz
Silicon Dioxide (SiO2)
Fluorite on Host Rock
Calcium Fluoride (CaF2)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Red Garnet
Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)
Milky Quartz
Silicon Dioxide (SiO2)