Bauxite
Bauxite (Al2O3·2H2O)
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Bauxite
Bauxite (Al2O3·2H2O)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Man-made Synthetic Material (Costume Faux Fur)
Synthetic Polymer (Polyester/Acrylic)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Shale with Coprolite influence
Argillaceous sedimentary rock (Shale/Mudstone)
Banded Chert
Cryptocrystalline Quartz (SiO2)
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Sandstone
Arenite (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Obsidian
Volcanic glass
Felted Quartz / Chlorite Quartz
Chlorite included Quartz (SiO2 + (Mg,Fe)3(Si,Al)2O5(OH)4)
Green Fluorite
Calcium Fluoride (CaF2)
Quartz with impurities or Host Rock
SiO2 (Silicon Dioxide) with mixed silicates
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Quartz Pebble
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Pink Dyed Agate (Pink Agate Slice)
Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz
Sandstone (Ferruginous)
Arenite (Fe-rich)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Limonite (Ironstone)
FeO(OH)·nH2O (Hydrous ferric oxides)
Fluorite
Calcium Fluoride (CaF2)
Granitic Pegmatite
Granitic Pegmatite (principally Quartz, Feldspar, and Mica)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Silicon Carbide (Carborundum)
Moissanite (SiC)
Quartzwacke / Impure Sandstone
Arenite with minor lithic fragments (Silicon Dioxide matrix)
Pegmatite
Granitic Pegmatite
Orthoclase Feldspar
KAlSi3O8 (Potassium aluminum silicate)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Sandstone
Arenite
Lepidolite
Lepidolite [K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2]
Gold-bearing Quartz with Iron Oxides
Quartz (SiO2) with Limonite/Goethite (FeO(OH)) and Pyrite (FeS2)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Geode (unopened nodule)
Silicon Dioxide (SiO2) Nodule
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous matrix
Greenstone
Greenschist / Greenstone (Chlorite-Epidote facies)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities