Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Not A Mineral) in the encyclopedia
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Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Rough Precious Opal
Hydrated Silica (SiO2·nH2O)
mineral
Potassium Feldspar
Orthoclase (KAlSi3O8)
mineral
Sunstone
Oligoclase (Plagioclase Feldspar Group) - (Ca, Na)(Al, Si)4O8
mineral
Sodalite
Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)
mineral
Chrysoberyl (Cyclic Twin)
Beryllium Aluminum Oxide (BeAl2O4)
mineral
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Iron Oxide or Chlorite
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron traces)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Amazonite
Potassium Feldspar (Microcline) - K(AlSi3O8)
Mineral
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Yellow Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
sedimentary/mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
mineral
Citrine (Heat-treated Amethyst)
Silicon Dioxide (SiO2) with iron impurities
mineral
Quartz (Citrine or Smoky variant)
Silicon Dioxide (SiO2)
mineral
Oceanside Agate (Orbicular Agate)
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Quartz (Clear/White)
Silicon Dioxide (SiO2)
mineral
Quartz (Crystal)
Silicon Dioxide (SiO2)
mineral
Chert (varieties include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Prehnite
Calcium aluminum silicate hydroxide - Ca2Al(AlSi3O10)(OH)2
mineral
Epidote in Matrix (likely Amphibolite or Gneiss)
Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH)) in Metamorphic Matrix
metamorphic
Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide)
Mineral
Banded Agate (Lake Superior Agate style)
Cryptocrystalline Quartz (SiO2)
mineral
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
mineral
Chert (often called Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (specifically Flint or Gray Chert)
Silicon Dioxide (Microcrystalline Quartz), SiO2
sedimentary
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Brown Jasper (Likely)
Jasper (Cryptocrystalline Silicon Dioxide - SiO2)
Mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Citrine or Yellow Quartz
Silicon Dioxide (SiO2) with iron impurities
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Eagle Eye / Grey Tiger Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
metamorphic
Amethyst and Citrine (Ametrine Mix)
Silicon Dioxide (SiO2) with Fe3+ impurities
mineral