Limestone
Calcium Carbonate (CaCO3)
Category
Browse mineral, possibly rock fragment containing a mineral specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Granite Cobble
Granitoid (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Mica minerals)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Amber
Succinite (organic fossilized resin)
Marble
Recrystallized Calcite / Dolomite (CaCO3)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2 (Lithium-bearing mica)
Fossiliferous Limestone with Rugose Coral
Rugosa (order), typically preserved in CaCO3 (Calcite)
Banded Gneiss
Gneiss (pronounced "nice")
Gneiss
Gneiss (a metamorphic rock)
Limestone
Calcium Carbonate (CaCO3)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Chert (containing small fossils)
Chert (Microcrystalline Quartz, SiO2)
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Silver (Native Silver Mineral)
Ag (Native Silver), Alloyed 90% Ag / 10% Cu
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
Milky Quartz with Country Rock contact
Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock
Basalt
Basalt (containing mainly Plagioclase feldspar and Pyroxene)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Basalt Pebble
Basalt (Extrusive Mafic Igneous)
Sapphire (Corundum)
Corundum (Al2O3), variety Sapphire
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Chert (containing Calcite or Quartz inclusions)
Silicon Dioxide (SiO2) with varying mineral impurities
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with included minerals (Fuchsite for green)
Basalt (Water-worn Pebble)
Basalt (Mafic Extrusive Igneous Rock)
Fossiliferous Limestone
Calcite (CaCO3) with Bioclastic inclusions
Coquina
Bioclastic Limestone
Gold Nugget / Gold-bearing Quartz
Native Gold (Au)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Tektite (likely Australite)
Tektite (no specific chemical formula as it's a natural glass of variable composition, mostly SiO2, Al2O3, FeO, MgO, CaO, K2O, Na2O, TiO2)
Basalt (Road Gravel)
Aphanitic mafic volcanic rock (various compositions of plagioclase feldspar and pyroxene)
Agate
Agate (Cryptocrystalline Variety of Quartz, SiO2)
Mica Schist
Mica Schist (Composition typically includes Muscovite KAl2(AlSi3O10)(OH)2 and Quartz SiO2)
Amethyst
Quartz (SiO2) with trace iron impurities
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Quartz
Silicon dioxide (SiO2)
Green Aventurine
Aventurine (a variety of Quartz, SiO2)
Quartz (Small fragments)
Silicon Dioxide (SiO2)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper (Imperial Jasper style)
Silicon Dioxide (SiO2) with impurities
Limonite and Goethite on Gossan
FeO(OH)·nH2O