Obsidian and Phantom Quartz
Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Obsidian and Phantom Quartz
Volcanic Glass (SiO2 + MgO + Fe3O4) and Crystalline Quartz (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Green Quartz (Prasiolite variant or Aventurine)
Silicon Dioxide (SiO2)
Vesuvianite (Idocrase)
Ca19(Al, Mg, Fe)13(SiO4)10(Si2O7)4(OH, F, O)10
Garnet
Almandine (Fe3Al2(SiO4)3)
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst (Raw Cluster)
Silicon Dioxide with iron impurities (SiO2)
Yellow Quartz
Silicon Dioxide (SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4
Pink Dyed Agate Geode Slice
Cryptocrystalline Quartz (SiO2)
Citrine
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
Amethyst (Druzy Quartz)
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Blue Chalcedony
Cryptocrystalline Quartz (SiO2)
Citrine
Silicon dioxide (SiO2)
Quartz (Milky or Smoky Quartz Pebble)
Silicon Dioxide (SiO2)
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with fibrous inclusions (commonly Dumortierite)
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8) with Albite
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Citrine
Silicon Dioxide (SiO2)
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Red Garnet (likely Almandine)
Almandine (Fe3Al2(SiO4)3)
Chalcedony (Botryoidal/Tumbled Agate)
Silicon Dioxide (SiO2)
Peridot
Olivine ((Mg, Fe)2SiO4)
Opal
Hydrated amorphous silica (SiO2·nH2O)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Peridot
Olivine ((Mg, Fe)2SiO4)
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
Quartz Pebble (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)
Sunstone
(Ca,Na)(Al,Si)4O8 (Oligoclase or Andesine)
Amazonite
Microcline (KAlSi3O8) with trace lead (Pb)
Moonstone (Rainbow Moonstone)
Labradorite (White Labradorite) - (Na,Ca)(Al,Si)4O8
Ametrine
Ametrine (SiO2 - Silicon Dioxide with varied iron impurities)
Agate Geode Slice (with Druzy Quartz)
Silicon Dioxide (SiO2)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)