Obsidian
Volcanic Glass (SiO2 + minor impurities)
Category
Browse manufactured glass specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2 + minor impurities)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Quartz
Silicon Dioxide (SiO₂)
Obsidian
Volcanic glass
Obsidian
Volcanic glass
Obsidian
Volcanic glass
Blue Goldstone
Aventurine Glass
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Opalite (Man-made Glass)
Synthetic Opalised Glass
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Blue Goldstone
Aventurine Glass (SiO2 with Cobalt/Copper inclusions)
Muscovite Mica
KAl2(AlSi3O10)(F,OH)2
Muscovite Mica (with Quartz matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
Blue Goldstone
Aventurine Glass (Silicon Dioxide with metal inclusions)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Obsidian (Volcanic Glass)
Sulfur
Sulfur (S8)
Shale
Fissile mudrock (composed of clay-sized particles and detrital grains)
Tiffany Stone
Bertrandite Fluorite (CaF2 + Be4Si2O7(OH)2)
Magnetite (Lodestone variety)
Magnetite (Iron(II,III) oxide, Fe3O4)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Fluorite (Purple variety)
Calcium Fluoride (CaF2)
Fluorite
Calcium Fluoride (CaF2)
Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite)
Calcium Fluoride (CaF2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
Pyrite
Iron Sulfide (FeS2)
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
Calcite
Calcium Carbonate (CaCO3)
Specular Hematite and Magnetite Ore
Iron Oxide (Fe2O3 and Fe3O4)
Diamond (in a jewelry setting)
Cubic Carbon (C)
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Fluorite
Calcium Fluoride (CaF2)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Limestone
Calcium Carbonate (CaCO3)
Sea Glass (Turquoise/Aqua)
Amorphous Silica (SiO2) with transition metal dopants
Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)