Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
Smoky Quartz and Feldspar Pegmatite
Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)
Pyrite and Fluorite on Quartz (Matrix Specimen)
Iron Disulfide (FeS2) and Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
Pegmatite (Granite Pegmatite)
Intrusive Igneous Rock (Granite Pegmatite)
Amazonite
Potassium aluminum silicate (KAlSi3O8)
Tanzanite (Rough)
Blue Zoisite (Ca2Al3(SiO4)3(OH))
Malachite and Azurite on Matrix
Cu2CO3(OH)2 (Malachite) / Cu3(CO3)2(OH)2 (Azurite)
Peacock Ore
Bornite (Cu5FeS4)
Rutilated Quartz
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
Amethyst
Amethyst (Silicon Dioxide with iron impurities), SiO2
Amethyst
Amethyst (SiO2 with Iron impurities)
Rough Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Stichtite in Serpentine (Atlantasite)
Mg6Cr2CO3(OH)16·4H2O in Mg3Si2O5(OH)4
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
Vanadinite on Matrix
Vanadinite (Pb5(VO4)3Cl)
Chalcedony (Yellow Agate)
Cryptocrystalline Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Emerald (Faceted Gemstone)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Quartz Geode
Quartz (Silicon Dioxide, SiO2) Geode
Desert Rose
Gypsum (variety Selenite) or Barite, CaSO4·2H2O
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amethyst
Crystalline Quartz (SiO2) with iron impurities
Herkimer Diamond (Quartz)
Silicon Dioxide (SiO2)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Opal
Hydrated silica (SiO2·nH2O)
Amethyst
Quartz (Silicon Dioxide with iron impurities), SiO2
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Amethyst (Quartz variety)
Silicon Dioxide (SiO2) with iron impurities
Zoisite with Ruby / Anyolite
Anyolite (Ca2Al3(SiO4)3(OH) with Chromian Zoisite and Tschermakite inclusions)
Chalcedony with Druzy Quartz Geode
Silicon Dioxide (SiO2)
Sapphire (Corundum)
Corundum (Al2O3), variety Sapphire
Sandstone
Arenite (SiO2 based with mineral cement)
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Quartz (Fieldstone/Pebble)
Silicon Dioxide (SiO2)
Indigo Gabbro
Gabbro (MaFIC intrusive rock)
Blue Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Blue Dyed Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2