Diamond
Diamond (C)
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Diamond
Diamond (C)
Sandstone
Arenite (SiO2 based)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Obsidian
Extrusive igneous volcanic glass (rich in SiO2)
Hematite (Iron Ore)
Hematite (Fe2O3)
Clear Quartz
Silicon Dioxide (SiO2)
Gemstone Sand (Mineral Assortment)
Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)
Agate (specifically, multi-colored or pastel-dyed agate)
Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).
Mica Schist
Schist (Crystalline metamorphic rock)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Sandstone
Sandstone (Sedimentary rock composed of silicate grains)
Sandstone (specifically Cross-bedded Sandstone)
Arenite (composed primarily of SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Peacock Ore
Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)
Dendritic Agate
Silicon Dioxide with Manganese/Iron oxide inclusions (SiO2)
Granite Gneiss with Garnet
Garnetiferous Gneiss
Chert (varieties include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions
Agate
Silicon dioxide (SiO2)
Fluorite (Rainbow, Purple-Blue Tumbled)
Calcium Fluoride (CaF2)
Quartz (Milky or Iron-Stained)
Silicon Dioxide (SiO2)
Geode (Unbroken)
Silicon Dioxide (SiO2) usually as Microcrystalline Quartz or Chalcedony
Quartz / Quartz Geode fragment
Silicon Dioxide (SiO2)
Bronzite
Enstatite (var. Bronzite), (Mg,Fe)SiO3
Magnetite (Lodestone variety)
Magnetite (Iron(II,III) oxide, Fe3O4)
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
Blue Quartzite (River Pebble)
Quartzite (primarily SiO2 with Dumortierite or Crocidolite inclusions)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Specular Hematite
Specularite (Iron Oxide, Fe2O3)
Obsidian
Volcanic Glass (SiO2 rich)
Schist
Mica Schist (Medium-grade metamorphic rock)
Quartz (Chert/Chalcedony Variety)
Silicon Dioxide (SiO2)
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
Tiger's Eye (Tumbled Blue/Black-Golden variety)
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)
Goethite
Goethite (α-FeO(OH))
Quartz
Silicon Dioxide (SiO₂)
Glauconite
(K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Obsidian
Volcanic Glass (SiO2)
Amethyst
Crystalline Quartz (SiO2) with iron impurities
Orthoclase Feldspar
Orthoclase (KAlSi3O8)