Quartz
Silicon Dioxide (SiO2)
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Clear Quartz (Double Terminated)
Silicon Dioxide (SiO2)
mineral
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Igneous
Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
mineral
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Quartz
Quartz (SiO₂)
Mineral
Olivine (likely Peridot variety)
Olivine Mineral Group (specifically Forsterite-Fayalite solid solution series); Chemical formula: (Mg,Fe)2SiO4
Mineral
Sunstone (variety of Feldspar)
Oligoclase Sunstone, Plagioclase Feldspar (Na,Ca)Al(Si,Al)Si2O8
Mineral
Jasper (specifically Brecciated or Agated Jasper)
Silicon Dioxide (SiO2) - Chalcedony with impurities
Mineral / Sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Jade (Nephrite or Jadeite)
Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2 (amphibole mineral); Jadeite: NaAlSi2O6 (pyroxene mineral)
Metamorphic Rock / Mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Diopside (likely Chromian Diopside)
Diopside, part of Clinopyroxene family of inosilicates. Chemical formula: CaMgSi2O6. The green variety is often Chromian Diopside due to chromium impurities.
mineral
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Mineral
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
igneous
Blue Quartzite (Blue Aventurine / Dumortierite Quartz)
Quartzite with inclusions (SiO2 with AlAl4BSi3O18)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Peridot
Olivine (specific variety: gem-quality forsterite), (Mg,Fe)2SiO4
Mineral
Granitic Pegmatite
Granitic Pegmatite (principally Quartz, Feldspar, and Mica)
igneous
Diamond (Macled/Crystal fragment)
Carbon (C), isometric crystal system
mineral
Rhodonite with Manganese Oxides
Rhodonite (Mn,Fe,Mg,Ca)SiO3
metamorphic
Carnelian Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
mineral
Turquoise
Hydrous phosphate of copper and aluminum (CuAl6(PO4)4(OH)8·4H2O)
mineral
Quartz (Rose or Milky variety fragment)
Silicon Dioxide (SiO2)
mineral
Garnet (specifically Almandine)
Almandine - Fe3Al2(SiO4)3
metamorphic
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Amethyst
Amethyst (Silicon Dioxide with iron impurities), SiO2
mineral
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Mineral
Natural Gemstone Cabochons (Ruby, Moonstone, Emerald, Citrine)
Ruby (Al2O3:Cr), Moonstone (KAlSi3O8), Emerald (Be3Al2(SiO3)6:Cr), Citrine (SiO2)
mineral
Black Star Diopside (beads)
Diopside (CaMgSi2O6) - a member of the pyroxene group
Mineral
Lepidolite
K(Li,Al)3(Al,Si)4O10(F,OH)2 (Lithium-bearing phyllosilicate)
mineral
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite, Sodalite, Calcite, and Pyrite)
Mineral
Granitic Pegmatite with Schorl
Granitic Pegmatite (Schorl: NaFe3Al6(Si6O18)(BO3)3(OH)3OH)
igneous
Olivine (Peridotite)
Olivine Group; (Mg, Fe)2SiO4
igneous
Tiger's Eye
Tiger's Eye (a variety of Quartz, SiO₂)
Mineral (specifically a gemstone variety)
Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Smoky Quartz
SiO2 (Silicon Dioxide)
Mineral