Potassium Feldspar
K-Feldspar (Orthoclase/Microcline) KAlSi3O8
Category
Browse organic gemstone (sedimentary classification) specimens identified by the Rock Identifier community.
Potassium Feldspar
K-Feldspar (Orthoclase/Microcline) KAlSi3O8
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Jasper
Cryptocrystalline Quartz (SiO2)
Carnelian
Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)
Chert (Nodule)
Chert (variety of microcrystalline quartz, SiO2)
Green Chalcedony
Silicon Dioxide (SiO2) with trace minerals
Clear Quartz
Silicon Dioxide (SiO2)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Quartz Geode (Cracked)
Silicon Dioxide (SiO2)
Agate (Chalcedony)
Silicon Dioxide (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Chalcedony (Botryoidal/Chalcedony Rose)
Silicon Dioxide (SiO2)
Fluorite
Calcium fluoride (CaF2)
Garnet (Almandine)
Almandine, Fe3Al2Si3O12
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (specifically Milky or Clear Quartz)
Silicon Dioxide (SiO2)
Black Opal
Hydrated Silica (SiO2·nH2O)
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Petoskey Stone (Fossilized Coral)
Hexagonaria percarinata (CaCO3)
Turquoise
Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Chert (Jasper variety)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Ocean Jasper (Orbicular Jasper)
Spherulitic Chalcedony (SiO2)
Yellow Jasper
Chalcedony (SiO2) with iron inclusions
Desert Rose (Gypsum/Barite)
Gypsum (CaSO4·2H2O) or Barite (BaSO4) inclusion
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron inclusions
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Carnelian
Chalcedony (SiO2) with Iron Oxide inclusions
Carnelian
Carnelian (Silicon Dioxide - SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Opal
Hydrated amorphous form of silica (SiO2·nH2O)
Jasper
Silicon dioxide (SiO2) with impurities
Precious Opal
Hydrated amorphous silica (SiO2·nH2O)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Pyrite and Sunstone
Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)
Carnelian
Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)
Graphite
Graphite (C)
Quartz
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Silicon Dioxide, SiO2)