Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Category
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Shark Tooth Fossil
Otodus sp. (possibly Cretalamna)
Petrified Wood
Silicified Wood (primarily SiO2)
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Moldavite
Tektite (Impact Glass), ~80% SiO2 + Al2O3
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Mixed Mineral Collection (Quartz, Amethyst, Rose Quartz, Pyrite, etc.)
Mixed Silicates and Sulfides (SiO2, FeS2)
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Pyrite (on host rock)
Iron Sulfide (FeS2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Smoky Quartz
Silicon Dioxide (SiO2)
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
Chert (River Pebble)
Microcrystalline silica (SiO2)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Green Aventurine
Silicon dioxide with Fuscite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
Chert (Flint)
Silicon Dioxide (SiO2)
Ruby (Raw Corundum)
Corundum (Al2O3) with Chromium traces
Chert with Quartz Druzy
Microcrystalline Quartz (SiO2) with Drusy Quartz Coating
Schorl (Black Tourmaline)
NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Quartz
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Amazonite
Microcline (K(AlSi3O8))
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide impurities
Jasper
Silicon Dioxide (SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Pearl
Calcium carbonate (CaCO3) - Aragonite/Calcite variety
Banded Chert
Cryptocrystalline Quartz (SiO2)
Rhodochrosite
Rhodochrosite, Manganese Carbonate (MnCO3)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Chert (specifically Flint or Common Chert)
Chert (Cryptocrystalline Silica, SiO2)
Lapis Lazuli
Sodium aluminum silicate with sulfur (main component: Lazurite [(Na,Ca)8(AlSiO4)6(SO4,S,Cl)2])
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)