Opal
Hydrated Silica (SiO2·nH2O)
Category
Browse sedimentary specimens identified by the Rock Identifier community.
Opal
Hydrated Silica (SiO2·nH2O)
Yellow Jasper
Chalcedony (SiO2) with iron oxide inclusions
Chalcedony (Botryoidal/Tumbled Agate)
Silicon Dioxide (SiO2)
Satin Spar (often marketed as Selenite)
Fibrous Gypsum (CaSO4·2H2O)
Jasper
Silicon dioxide (SiO2)
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Chert / Yellow Jasper
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Muscovite Schist
Mica Schist (primarily KAl2(AlSi3O10)(OH)2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Red Jasper
Silicon dioxide (SiO2) with iron inclusions
Fluorite
Calcium Fluoride (CaF2)
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Chert (and Flint)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (Flint variety)
Microcrystalline Quartz (SiO2)
Blue Lace Agate
Silicon Dioxide (SiO2) - Chalcedony / Quartz
Quartz (Common or Milky Quartz)
Silicon Dioxide (SiO2)
Red Dyed Howlite
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Gneiss (Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)
Carnelian
Chalcedony (SiO2)
Gold Nugget
Native Gold (Au)
Chert (with Limestone matrix)
Chert (Silica: SiO2)
Jasper
Silicon dioxide (SiO2)
Jasper with Quartz
Silicon Dioxide (SiO2) - Chalcedony variety
Gneiss
Gneiss (High-grade Metamorphic Rock)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Pyrite (Iron Pyrite)
Iron Disulfide (FeS2)
Quartz (Milky/Crystalline)
Quartz (Silicon Dioxide, SiO2)
Yellow Aventurine (or Citrine-colored Quartz)
Silicon Dioxide (SiO2) with inclusions
Gneiss (Banded Gneiss)
Gneiss
Chalcedony (Smoky Quartz or Agate nodule fragment)
Silicon Dioxide (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
Gold
Native Gold (Au)