Red Sandstone (Arkose)
Clastic Sedimentary Rock (Lithic Arkose)
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Red Sandstone (Arkose)
Clastic Sedimentary Rock (Lithic Arkose)
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
Blue Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of asbestiform silicates)
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)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
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
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Lake Superior Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Cinnabar in Matrix
Cinnabar (Mercury(II) sulfide, HgS)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Citrine Quartz
Silicon Dioxide (SiO2)
Tiger's Eye (Unpolished)
Pseudomorph of Quartz after Crocidolite (SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with FeOx inclusions
Ocean Jasper
Spherulitic Chalcedony (SiO2)
Aventurine (Green)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Bloodstone (Heliotrope)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite or Chlorite
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz (likely Herkimer Diamond style)
Silicon Dioxide (SiO2)
Amethyst (Faceted)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Sunstone
Aventurine Feldspar (composition: (Ca,Na)((Al,Si)2Si2O8))
Mookaite Jasper
Silicified Radiolarite (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Blue Lace Agate
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Rose Quartz Druzy
Silicon Dioxide (SiO2)
Peridot
Olivine ((Mg, Fe)2SiO4)
Garnet (specifically Almandine)
Almandine (Fe3Al2(SiO4)3)
Smoky Quartz
Silicon Dioxide (SiO2)
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)