Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Category
Browse mineral (primary constituent) specimens identified by the Rock Identifier community.
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2) with iron impurities
Bloodstone
Heliotrope (Cryptocrystalline Quartz, SiO2)
Carnelian
Carnelian (Chert/Chalcedony) - SiO2
Biotite Schist
Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]
Amethyst
Amethyst (Purple Quartz); formula: SiO2 (Silicon Dioxide)
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Druzy Quartz
Crystalline Silicon Dioxide (SiO2)
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
Amethyst (Chevron/Dream Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Mookaite Jasper
Silicified radiolarite (SiO2)
Amethyst Quartz with Matrix
Silicon Dioxide (SiO2)
Basalt with Hematite staining
Extrusive mafic igneous rock with Fe2O3
Mookaite Jasper
Radiolarite (Chert/Jasper variety), formula SiO2
Lake Superior Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Milky Quartz with Chlorite inclusions
Silicon Dioxide (SiO2) with Chlorite group minerals
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with FeOx inclusions
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite or Chlorite
Amygdaloidal Basalt
Amygdaloidal Basalt (with secondary mineral infilling)
Sunstone
Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))
Mookaite Jasper
Silicified Radiolarite (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Rose Quartz Druzy
Silicon Dioxide (SiO2)
Peridot
Olivine ((Mg, Fe)2SiO4)
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Jasper (Green)
Silicon Dioxide (SiO2) with impurities
Chlorastrolite (Greenstone)
Chlorastrolite (Pumpellyite variety), Ca2(Mg,Fe)Al2(SiO4)(Si2O7)(OH)2·H2O
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2 + Mn/Fe)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate)
Granite Thin Section
Granitic rock (Phaneritic texture)
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Biotite Schist with Garnet
Garnet-Biotite Schist
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Felted Quartz / Chlorite Quartz
Chlorite included Quartz (SiO2 + (Mg,Fe)3(Si,Al)2O5(OH)4)
Common Opal
Hydrated amorphous form of silica (SiO2·nH2O)