Rough Corundum (likely Sapphire or Common Corundum)
Aluminum oxide (Al2O3)
Category
Browse industrial byproduct (often confused with igneous rocks or meteorites) specimens identified by the Rock Identifier community.
Rough Corundum (likely Sapphire or Common Corundum)
Aluminum oxide (Al2O3)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Magnetite (Lodestone variety)
Magnetite (Iron(II,III) oxide, Fe3O4)
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite or Goethite inclusions
Diorite
Phaneritic Intermediate Plutonic Rock (Diorite)
Epidote in Matrix
Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Magnetite
Magnetite (Fe3O4)
Almandine Garnet
Almandite (Fe3Al2(SiO4)3)
Pink Garnet (likely Almandine or Rhodolite)
Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
Banded Chalcedony (Agate)
Chalcedony (SiO2) - Cryptocrystalline Quartz
Garnet
Garnet Group (Silicate mineral); general formula X3Y2(SiO4)3
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
White Topaz
Aluminum Silicate Fluoride Hydroxide, Al2SiO4(F,OH)2
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Quartz (Iron-Stained Quartz Pebble)
Silicon Dioxide (SiO2)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Polygenetic Breccia
Clastic Breccia (containing lithic fragments in a fine-grained matrix)
Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
Yellow Quartz
Silicon Dioxide (SiO2)
Amazonite
Amazonite (KAlSi3O8)
Amazonite
Amazonite / Microcline (KAlSi3O8)
Ruby
Corundum (Aluminium Oxide with Chromium impurities, Al2O3:Cr)
Quartz Pebble
Silicon Dioxide (SiO2)
Scoria (Lava Rock)
Scoria (Mafic Volcanic Rock)
Quartz Druze on Matrix (Geode Fragment)
Quartz (Silicon Dioxide, SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Rough Gemstone Grains (Mixed Sapphires and Quartz)
Corundum (Al2O3) and Quartz (SiO2)
Garnet (likely Almandine or Pyrope)
Garnet Group, Nesosilicates (Complex chemistry, e.g., Almandine: Fe3Al2Si3O12)
Quartz Geode
Silicon dioxide (SiO2)
Citrine
Quartz (SiO2) - variety Citrine
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Citrine
Quartz (SiO₂) variety
Magnetite
Magnetite (Fe3O4)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Black Sapphire
Corundum (Al2O3)
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Basalt with Desert Varnish
Mafic Volcanic Rock (Fe/Mg rich Silicate)
Green Aventurine
SiO2 (Silicon Dioxide) with Fuchsite inclusions
Scoria
Scoria (a vesicular basalt or andesite)
Serpentine
Serpentine group minerals (e.g., Antigorite, Chrysotile, Lizardite). Chemical formula: (Mg, Fe)₃Si₂O₅(OH)₄