Sandstone
Arenite (primarily SiO2)
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Sandstone pebble
Sandstone (mainly Quartz, SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Desert Rose (Baryte or Gypsum rosette)
Baryte (BaSO4) or Gypsum (CaSO4·2H2O)
Agate Geode Node
Cryptocrystalline Quartz (SiO2)
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
Amazonite
Potassium Feldspar (KAlSi3O8)
Amazonite
Amazonite (KAlSi3O8)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geode
Prehnite
Ca2Al2Si3O10(OH)2
Quartz Geode
Silicon Dioxide (SiO2)
Muscovite
Muscovite, KAl2(AlSi3O10)(OH)2
Sandstone
Sedimentary Rock (Quartz Arenite)
Sandstone with Manganese Dendrites
Arenite (mostly SiO2) with Manganese Oxide inclusions (MnO2)
Greenstone or Epidote-rich Metamorphic Rock
Chlorite/Epidote Schist or Greenstone
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Clear Quartz
Silicon Dioxide (SiO2)
Fossilized turtle shell or carapace fragment
Indeterminate Testudines; likely a fossil turtle carapace scute/bone
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Mica Schist
Schist
Schist
Schist
Blue Apatite
Fluorapatite / Apatite (Ca5(PO4)3(F,Cl,OH))
Blue slag-like mineral specimen, possibly bornite or chalcopyrite
Tentatively bornite (Cu5FeS4) or iridescent chalcopyrite (CuFeS2)
Blue quartz-like mineral specimen
Likely quartz (SiO₂), possibly dyed or coated; exact identification requires testing
Limonite Nodules / Goethite
Hydrated Iron Oxide-Hydroxide (FeO(OH)·nH2O / Fe2O3·nH2O)
Quartz Vein in Basalt or Mafic Rock
Silicon Dioxide (SiO2) vein in volcanic/mafic matrix
Bauxite
Bauxite (Al2O3·nH2O)
Schist with Quartz/Mica
Mica Schist (primarily Muscovite and Quartz)
Granite
Intrusive Felsic Igneous Rock
Red Sandstone (Iron-stained)
Clastic sedimentary rock (primarily Quartz with Iron Oxides)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (Lithic arenite / Quartz arenite)
Quartz (Small Grains)
Silicon Dioxide (SiO2)
Pegmatite
Igneous Pegmatite
Black Tourmaline
Schorl (NaFe2+3Al6(BO3)3Si6O18(OH)4)
Pink Garnet (likely Almandine or Rhodolite)
Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)
Granite
Phaneritic intrusive igneous rock (Quartz, Feldspar, Mica)
Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)