Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Mineral, Organic Gemstone
Browse mineral, organic gemstone specimens identified by the Rock Identifier community.
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
mineral
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Mookaite Jasper
Silicified radiolarite (SiO2)
sedimentary
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
mineral
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
mineral
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite or Chlorite
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Tiger's Eye (Unpolished)
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Mookaite Jasper
Radiolarite (Chert/Jasper variety), formula SiO2
sedimentary
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Lake Superior Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Sunstone
Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Beryl (Emerald or Aquamarine in Matrix)
Beryllium Aluminum Silicate (Be3Al2Si6O18)
mineral
Aquamarine (Beryl)
Beryllium aluminum silicate (Be3Al2Si6O18)
mineral
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
mineral
Chlorastrolite (Greenstone)
Chlorastrolite (Pumpellyite variety), Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2·H2O
mineral
Peridot
Olivine ((Mg, Fe)2SiO4)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
Amethyst (Varietal of Quartz), SiO2 (Silicon Dioxide)
mineral
Sunstone
Orthoclase or Oligoclase Feldspar (Na,Ca)(Al,Si)4O8
mineral
Amethyst
Quartz (Silicon Dioxide) with Iron impurities, SiO2
mineral
Amethyst (Quartz Variety)
Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)
mineral
Sunstone
Oligoclase (a plagioclase feldspar variant), (Na,Ca)(Al,Si)4O8
mineral
Amethyst (Chevron or Banded variety)
Silicon Dioxide (SiO2) with iron impurities
mineral
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
sedimentary
Orthoclase Feldspar with Quartz
Orthoclase (KAlSi3O8)
mineral
Sodalite
Na8(Al6Si6O24)Cl2
mineral
Black Tourmaline (Schorl)
Sodium Iron Aluminum Borosilicate (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
mineral
Chrysocolla
Hydrated copper silicates (Cu, Al)2H2Si2O5(OH)4·nH2O
mineral
Amazonite
Amazonite (KAlSi3O8)
mineral
Citrine
Silicon Dioxide (SiO2)
mineral
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
metamorphic
Moonstone (Feldspar variety)
Orthoclase Feldspar (KAlSi3O8)
mineral
Yellow Topaz (Imperial or Precious Topaz)
Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)
mineral
K2 Jasper (K2 Granite)
Azurite in Granite (Al2Cu3(CO3)2(OH)2 in NaAlSi3O8)
igneous
Citrine
Silicon Dioxide (SiO₂)
mineral