Obsidian
Volcanic Glass (SiO2 rich)
Category
Browse crystal specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2 rich)
Agate with Quartz Druzy
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties
Unakite
Epidotized Granite (SiO2, KAlSi3O8, Ca2(Al, Fe)3(SiO4)3(OH))
Celestite (Celestine)
Celestine (Strontium Sulfate, SrSO4)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Rhodochrosite
Manganese carbonate (MnCO3)
Porphyritic Basalt (or Porphyry)
Porphyritic Basalt (Mafic volcanic rock with phenocrysts)
Amazonite (with smoky quartz/feldspar inclusions)
K(AlSi3O8), Microcline (Tectosilicate)
Fluorite (Green Fluorite on Host Rock)
Fluorite (Calcium Fluoride, CaF2)
Halite (Rock Salt)
Halite (NaCl)
Hematite
Hematite (Iron(III) oxide, Fe2O3)
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
Granite Gneiss with Garnet
Garnetiferous Gneiss
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Pyrite
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Pyrite
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Smoky Quartz
Silicon Dioxide (SiO2)
Dumortierite Quartz (Blue Quartz)
Al7(BO3)(SiO4)3O3 / Quarz with Dumortierite inclusions
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Quartz with Pyrite
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Amethyst (Purple Quartz)
Silicon Dioxide (SiO2) with iron impurities
Quartzite
Quartzite (primarily SiO2)
Muscovite Mica (Granitic Pegmatite)
Muscovite - KAl2(AlSi3O10)(OH)2
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst (Tumbled)
Amethyst (Silicon Dioxide with Iron impurities) - SiO2
Green Fluorite
Calcium Fluoride (CaF2)
Amazonite
Microcline (KAlSi3O8) with Trace Lead
Eudialyte
Eudialyte (Na4(Ca,Ce)2(Fe2+,Mn,Y)ZrSi8O22(OH,Cl)2)
Quartz (specifically Milky or Clear Quartz)
Silicon Dioxide (SiO2)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Milky Quartz (or Vein Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rose Quartz
Quartz (Silicon Dioxide, SiO2) with trace inclusions of dumortierite
Granite
Phaneritic Felsic Igneous Rock
Quartz (Milky or Common Quartz)
Silicon Dioxide (SiO2)
Porphyry (specifically Porphyritic Rhyolite or Andesite)
Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)