Peridot
Olivine ((Mg, Fe)2SiO4)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Peridot
Olivine ((Mg, Fe)2SiO4)
Lapis Lazuli
Complex metamorphic rock containing Lazurite ((Na,Ca)8(AlSiO4)6(SO4,S,Cl)2), Calcite, and Pyrite
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
Diamond (appearing in jewelry)
Diamond (pure Carbon, C)
Garnet
Garnet Group (complex nesosilicates with general formula X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+, V3+)
Quartz
Quartz (SiO2)
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcedony replacement)
Aquamarine
Beryl (Be3Al2Si6O18)
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Calcite
Calcite (CaCO3)
Schist
Schist (metamorphic rock)
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Quartz Geode
Silicon Dioxide (SiO2)
Smoky Quartz
SiO2 (Silicon Dioxide)
Quartz (Crystal/Druzy Quartz)
Quartz (SiO₂)
Gneiss
Gneiss
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
Picture Jasper
Silicon Dioxide (SiO2) - Opaque Chert/Quartzite variety
Septarian Nodule
Septarian Concretion
Banded Chert
Cryptocrystalline Quartz (SiO2)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Grey River Stone (Gneiss/Schist mix)
Foliated Metamorphic Rock (variable mineral formula)
Cubic Zirconia (CZ)
Zirconium dioxide (ZrO2)
Chert (specifically Flint or Common Chert)
Chert (Cryptocrystalline Silica, SiO2)
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Basalt with Vesicles
Vesicular Basalt (comprising Plagioclase Feldspar, Pyroxene, and Olivine)
Fossil Coral (Rugosa or Solitary Coral)
Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)
Citrine Quartz
Citrine (Silicon Dioxide - SiO2)
Chert (specifically Flint or Jasper variant)
Chert (Siliceous rock composed of microcrystalline Quartz, SiO2)
Chert (often called Flint)
Chert (Microcrystalline Quartz, SiO2)
Gneiss
High-grade Metamorphic Gneiss
Unakite
Epidotized Granite
Quartz
Quartz (SiO2, Silicon Dioxide)
Banded Sandstone
Arenite with Liesegang banding (primarily SiO2 with FeO(OH) impurities)
Banded Chert
Cryptocrystalline Quartz (SiO2)
Amethyst (Faceted Gemstone)
Silicon Dioxide (SiO2) with iron impurities
Serpentine
Serpentine Group Minerals (e.g., Antigorite, Chrysotile, Lizardite)
Petrified Wood
Silicified Wood (SiO2)
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone
Chert (Jasper/Limonitic Chert)
Microcrystalline Quartz (SiO2)