Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Category
Browse gemstone specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Clear Quartz
Silicon Dioxide (SiO2)
Quartz (Small Pebble)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3(Si, Al, Fe)2O5(OH)4
Carnelian
Carnelian (Silicon Dioxide, SiO2)
Botryoidal Hematite (Kidney Ore)
Iron(III) oxide (Fe2O3)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Clear Quartz
Silicon Dioxide (SiO2)
Red Jasper (Chert)
Silicon Dioxide (SiO2)
Green Chalcedony (Green Agate)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Carnelian Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
Tiger's Eye (likely Hawk's Eye variant)
Pseudomorph of Quartz after Crocidolite (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Amber
Succinite (a variety of fossilized tree resin); chemical formula appx. C10H16O
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with microcrystalline structure
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Jasper
Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn,Fe,Mg,Ca)SiO3
Jasper
Jasper (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rose Quartz
Quartz (Silicon Dioxide) - SiO2
Blue Kyanite
Kyanite (Al2SiO5)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Montana Moss Agate
Chalcedony (Silicon Dioxide, SiO2)
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Tiger's Eye
Silicon Dioxide (SiO2) with fibrous inclusions of Crocidolite
Chrysocolla on Quartz
Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)
Aventurine (Green Quartz)
Quartz with Fuchsite inclusions (SiO2 with K(Al,Cr)2(AlSi3O10)(OH)2)
Feldspar (Orthoclase)
Potassium Feldspar (KAlSi3O8)
Chert
Chert (Microcrystalline Quartz, SiO2)
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
Moonstone (Feldspar)
Orthoclase/Albite ((K,Na)AlSi3O8)
Orange Calcite
Calcite (Calcium Carbonate, CaCO3)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Ruby (Raw Corundum)
Corundum (Al2O3) with Chromium traces
Amazonite
Amazonite (Microcline Feldspar) K(AlSi3O8)
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Clear Quartz
Silicon Dioxide (SiO2)