Amethyst
SiO2 (Silicon Dioxide with iron impurities)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
Blue Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of asbestiform silicates)
Red Beryl
Bixbite (Be3Al2Si6O18 with Mn3+ ions)
Citrine
Silicon Dioxide (SiO2) - Yellow Quartz variety
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Amazonite
Amazonite (KAlSi3O8); a green variety of Microcline feldspar
Amethyst
SiO2 (Silicon Dioxide) with Iron (Fe3+) impurities
Rough Citrine Quartz
Citrine (Silicon Dioxide, SiO2 with iron impurities)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Quartz (Chatoyant or Milky variety)
Silicon Dioxide (SiO2)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Chert (often called Flint when in chalk or limestone)
Silicon Dioxide (SiO₂)
Chert (Flinty variety)
Microcrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Chrysocolla
Hydrated copper silicate - Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
Petrified Wood
Silicified Wood (SiO2)
Moonstone (Tumbled)
Potassium Aluminum Silicate (KAlSi3O8) with inclusions of Albite
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz
Silicon dioxide (SiO2)
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Chert (and Chert Breccia)
Silicon Dioxide (SiO2)
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
K2 Jasper (K2 Granite)
Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)
Turquoise (Dyed Howlite or Magnesite imitation)
Hydrated phosphate of copper and aluminum / CuAl6(PO4)4(OH)8·4H2O
Jasper (Green/Yellow Moss Jasper)
Silicon Dioxide (SiO2)
Aquamarine
Beryl (Be₃Al₂Si‑₆O₁‑₈)
Citrine Quartz
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Citrine Quartz
Crystalline Quartz (SiO2) with iron impurities
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Amazonite
Microcline (KAlSi3O8 variant)
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Citrine
Citrine (Silicon Dioxide, SiO2)
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Sunstone
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
Amethyst
Amethyst (SiO2 with iron impurities)
Amethyst
Amethyst (Silicon Dioxide, SiO2)