Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Sandstone Pebble
Arenite (primarily SiO2)
Fairburn Agate
Cryptocrystalline Quartz (SiO2)
Rhodochrosite
Manganese carbonate (MnCO3)
Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
Sunstone
Oligoclase (Plagioclase Feldspar subclass), (Ca,Na)(Al,Si)4O8
Amethyst (Rough Crystal)
Silicon Dioxide (SiO2 with ferric iron impurities)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Citrine
Quartz (Silicon Dioxide - SiO2)
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
Amazonite
Amazonite (KAlSi3O8)
Rough Tanzanite
Zoisite (Ca2Al3(SiO4)3(OH))
Citrine (Heat-treated or Natural Quartz)
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Amethyst (SiO2 with iron impurities)
Amazonite
K(AlSi3O8) - Microcline variant
Moldavite
Moldavite (Siliceous vitreous substance)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Amazonite
Potassium aluminum silicate (Microcline); KAlSi3O8
Amazonite (or Amazon Stone)
Potassium Feldspar (Microcline), K(AlSi3O8)
Clear Quartz
SiO2 (Silicon Dioxide)
Amazonite
Microcline (Amazonstone), K(AlSi3O8)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Amazonite
Potassium Aluminum Silicate (KAlSi3O8)
Alexandrite
Chrysoberyl (BeAl2O4)
Amethyst
SiO2 (Silicon Dioxide with iron impurities)
Prasiolite (Green Quartz)
Silicon Dioxide (SiO2) with iron impurities
Carnelian
Chalcedony (SiO2) with Iron Oxide impurities
Aquamarine
Beryl (Be3Al2Si6O18 with Fe2+ impurities)
Blue Chalcedony
Chalcedony (SiO2)
Amazonite
K(AlSi3O8)
Amazonite
Microcline (KAlSi3O8)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amazonite
Microcline (KAlSi3O8) with Trace Elements
Sunstone
Oligoclase (Feldspar variety), (Na,Ca)(Si,Al)4O8
Chrysocolla in Quartz (Quantum Quattro variant)
Hydrated copper silicates (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) often mixed with SiO2