Black Obsidian
Volcanic Glass (SiO2 + impurities)
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Pyrite
Iron Disulfide (FeS2)
Basalt Water-Worn Pebble
Aphanitic Mafic Igneous Rock
Basalt
Basalt (Extrusive Mafic Igneous)
Granite
Phaneritic Felsic Igneous Rock (Main minerals: SiO2, KAlSi3O8, NaAlSi3O8)
Greenstone or Chlorite Schist
Greenschist / Chlorite schist
River Rock (Greywacke/Siltstone)
Siltstone / Argillaceous Greywacke
Jasper (specifically Red Jasper or Iron-stained Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
Blue Apatite
Chlorapatite / Fluorapatite (Ca5(PO4)3(F,Cl,OH))
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Schist
Mica Schist (formula variable based on mineral content, typically containing [K,Al,Fe,Mg,Si,O,H])
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with trace amounts of Chromium/Vanadium
Peacock Ore
Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
Sandstone (Flagstone)
Arenite (composed primarily of SiO2)
Granite
Granite (Felsic Plutonic Rock)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Moss Agate
SiO2 (Silicon Dioxide) with dendritic inclusions
Gold Ore in Quartz/Schist
Auriferous Quartz and Sulfide-bearing Schist
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Almandine Garnet
Almandine - Fe3Al2(SiO4)3
Jasper (Multi-color Chert)
Silicon dioxide (SiO2)
Granite
Granite (Phaneritic igneous rock)
Lemon Quartz (Orizaba/Citrinated Quartz)
Silicon Dioxide (SiO2) with iron impurities/treatment
Pink Granite
Phaneritic Felsic Igneous Plutonic Rock
Milky Quartz
Quartz (SiO2)
Gabbro
Plutonic mafic rock
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Smoky Quartz (Faceted Beads)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Carnelian
Carnelian (Silicon Dioxide - SiO2 with iron oxide impurities)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Chert (specifically Tan/Gray Chert)
Microcrystalline quartz (SiO2)
Quartzite
Quartzite (primarily SiO2)
Eye Agate (Sulemani Agate)
Banded Chalcedony (SiO2)
Jasper with Agate Inclusions
Silicon Dioxide (SiO2) - variety of Quartz/Chert
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Greenschist
Greenschist (Actinolite-Chlorite Schist)