Black Opal
Hydrated Silica (SiO2·nH2O)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Black Opal
Hydrated Silica (SiO2·nH2O)
Chalcedony (Quartz Pebbles)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Emerald and Diamond (Jewelry Setting)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities) and Carbon (C)
Quartz Crystal (Amethyst)
Silicon Dioxide (SiO2)
Clear Quartz
SiO2 (Silicon Dioxide)
Tanzanite
Blue/Violet Variety of Zoisite (Ca2Al3(SiO4)3(OH))
Milky Quartz
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Milky Quartz
Silicon Dioxide (SiO2)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides
Amazonite
Microcline (Amazonstone), K(AlSi3O8)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)
Amazonite
Microcline (K(AlSi3O8))
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Diamond
Carbon (C)
Jasper and Chert Conglomerate
Ferruginous Microcrystalline Quartz (SiO2)
Chert / Jasper
Silicon Dioxide (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Rhodochrosite
Manganese Carbonate (MnCO3)
Diamond
Diamond (pure Carbon, C)
Moonstone
Orthoclase feldspar ((K,Na)AlSi3O8)
Rough Diamond
Pure Carbon (C)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Red Jasper
Silicon Dioxide (SiO2)
Sunstone (Heliolite)
Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)
Smoky Quartz
Silicon Dioxide (SiO2)
Sunstone
(Ca,Na)((Al,Si)2Si2O8) - Plagioclase Feldspar
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
Agate (Lake Superior Agate variant)
Chalcedony / Silicon Dioxide (SiO2)
Garnet
Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3
Red Carnelian
Carnelian (Silicon Dioxide, SiO2)
Carnelian Agate
Carnelian (Silicon Dioxide, SiO2)
Jasper
Jasper (SiO2)
Zoisite with Ruby / Anyolite
Anyolite (Ca2Al3(SiO4)3(OH) with Chromian Zoisite and Tschermakite inclusions)
Agate
Banded Chalcedony (SiO2 - Silicon Dioxide)
Hardpan Nodule / Ferruginous Sandstone
Ferruginous Sandstone (Fe-cemented sediment)