Black Sapphire
Corundum (Al2O3 with iron and titanium impurities)
Category
Browse mineral, often found as a rock (metamorphic) specimens identified by the Rock Identifier community.
Black Sapphire
Corundum (Al2O3 with iron and titanium impurities)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
Citrine
Citrine (Silicon Dioxide, SiO2)
Sandstone (likely Iron-rich or Arkosic)
Arenite (SiO2 with FeO(OH) or Fe2O3 staining)
Staurolite (Cross Stone)
Staurolite (Fe2+2Al9Si4O23(OH))
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Orange Quartzite (River Pebble)
Quartzite (primarily SiO2)
Mica Schist
Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)
Quartz Geode
Silicon Dioxide (SiO2)
Epidote with Quartz and Feldspar
Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
River Pebble (Quartzite)
Quartzite (SiO2)
Sandstone (Quartzose Sandstone)
Arenite
Sodalite
Sodalite (Na4Al3Si3O12Cl)
Rough Gemstone Grains (Mixed Sapphires and Quartz)
Corundum (Al2O3) and Quartz (SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Yellow Aventurine
Silicon Dioxide (Quartz with inclusions of Mica or Pyrite), SiO2
Quartz Geode (River Cobble)
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Olivine in Basalt matrix
Peridotite (Mg, Fe)2SiO4
Quartz with Chlorite or Hornblende inclusions
Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Sandstone
Arenite (SiO2 based)
Pyrite
Iron Sulfide (FeS2)
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2 (Calcium magnesium iron silicate hydroxide)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Litharenite)
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Unakite
Unakite (altered granite)
Greenstone / Diorite
Intermediate plutonic igneous rock
Amethyst
Amethyst (SiO2 with iron impurities)
Yellow Ochre / Limonite
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Red Garnet (Almandine-Pyrope series)
Garnet Group, Almandine (Fe3Al2(SiO4)3) or Pyrope (Mg3Al2(SiO4)3)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Green Quartz (including Prase or Aventurine variants)
Silicon Dioxide (SiO2) with inclusions (likely Actinolite or Chlorite)
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
Pyrite
Iron Pyrite (FeS₂)
Mixed Tumbled Stones Collection
Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)
Raw Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium)
Sandstone
Arenite (primarily Quartz, SiO2)