Quartz (Druzy/Macro-crystalline)
Silicon Dioxide (SiO2)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Quartz (Druzy/Macro-crystalline)
Silicon Dioxide (SiO2)
Green Aventurine
Quartz (Silicon Dioxide, SiO2) with fuchsite inclusions
Turquoise (Dyed Howlite/Magnesite)
CuAl6(PO4)4(OH)8·4H2O (Natural Turquoise) or Ca2B5SiO9(OH)5 (Howlite)
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Pink Coral
Corallium rubrum (or related species, composed of calcium carbonate)
Chert (Jasper/Flint variation)
Chert (SiO2)
Quartz Crystal Rock
Silicon Dioxide (SiO2)
Jasper
Quartz (SiO2)
Quartz (Milky/Clear Variety)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Coal
Anthracite / Bituminous Coal
Chert
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (Permineralized organic matter, głównie $SiO_2$)
Limestone Pebble
Sedimentary carbonate rock (CaCO3)
Natural Freshwater Pearl
Calcium Carbonate (Aragonite and Calcite), CaCO3
Milky Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartz-rich rock, possibly milky quartz
Quartz (silicon dioxide, SiO₂), possibly with feldspar or mica inclusions
Lapis Lazuli
Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Quartz (Quartz Pebble)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Melo Melo Pearl (or Golden Chalcedony / Yellow Jasper Sphere)
Non-nacreous calcium carbonate pearl (or SiO2 - Silicon Dioxide)
Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Quartz (Milky or Smoky Quartz Pebble)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Silicon Dioxide (SiO2)
Tiger's Eye
Silicon dioxide (Quartz pseudomorph after crocidolite), SiO2
Amber
Succiniferous organic material (Succinite)
Amber
Succinited (C10H16O)
Amber
Succinite (Fossilized Tree Resin)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Zebra Rock / Zebra Marble
Banded Limestone-Marble Transition
Clear Quartz (Rock Crystal)
Crystalline Silicon Dioxide (SiO2)
Agate (or Chalcedony)
Silicon Dioxide (SiO2)
Limestone with Fossil Fragments
Bioclastic Carbonate Rock (CaCO3)
Agatized Chert / Chalcedony
Silicon Dioxide (SiO2)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Milky Quartz with Garnet/Hematite and Basalt
Silicon Dioxide (SiO2) with Almandine (Fe3Al2Si3O12) and Basalt
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)