Petrified Wood
Silicified Wood (SiO2)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Variscite in Matrix
Variscite (AlPO4 · 2H2O)
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Chrysocolla (with Quartz and Azurite)
Hydrated copper phyllosilicate mineral [Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)]
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ironstone Concretion
Siderite or Hematite Concretion
Moonstone
Orthoclase Feldspar (formula: (K,Na)AlSi3O8)
Sphalerite in Matrix (Polished Point)
Zinc sulfide (Zn,Fe)S
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
Rhodochrosite
Manganese Carbonate (MnCO3)
Quartz
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2)
Chert (Flint nodule)
Silicon dioxide (SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Chert (Nodule)
Silicon Dioxide (SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Liesegang Ring Siltstone
Siltstone with iron oxide Liesegang bands
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Pearl
Calcium carbonate (CaCO3) - Aragonite/Calcite variety
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Turquoise
CuAl6(PO4)4(OH)8·4H2O
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Amazonite in Pegmatite Matrix with Smoky Quartz
K(AlSi3O8) - Microcline (var. Amazonite) with SiO2 (Quartz)
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Mookaite Jasper
Silicified radiolarite (SiO2)
Mookaite Jasper
Radiolarite (Chert/Jasper variety), formula SiO2
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Lake Superior Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Citrine Quartz
Silicon Dioxide (SiO2)
Tiger's Eye (Unpolished)
Pseudomorph of Quartz after Crocidolite (SiO2)
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite or Chlorite
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Sunstone
Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))
Peridot
Olivine ((Mg, Fe)2SiO4)