Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
mineral
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
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Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Rose Quartz
Silicon dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Green Quartzite
Quartzite (SiO2)
metamorphic
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Sodalite
Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2)
mineral
Fossil Shark Tooth (Otodus obliquus)
Otodus obliquus; hydroxyapatite (mineralized form Ca5(PO4)3(OH))
sedimentary (fossiliferous)
Quartzite with Quartz Vein
Metamorphosed Quartz-rich Arenite (SiO2)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)
Metamorphic
Aquamarine
Beryl (Be3Al2Si6O18), specifically the blue-green variety
Mineral
Citrine
Citrine (Silicon Dioxide, SiO2)
mineral
Blue Topaz
Al2SiO4(F,OH)2 (Fluorine-bearing aluminum silicate)
mineral
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18
Mineral
Sodalite
Na8(Al6Si6O24)Cl2 (Sodalite)
mineral
Amethyst
Amethyst (variety of Quartz, SiO2)
mineral
Amazonite
K(AlSi3O8) - Lead-bearing Microcline (Tectosilicate)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Charoite
Charoite (K(Ca,Na)2Si4O10(OH,F)·nH2O)
metamorphic
Satin Spar (often marketed as Selenite)
Gypsum (CaSO4·2H2O)
mineral
Black Opal
Hydrated Amorphous Silica (SiO2 "n" H2O)
gemstone
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Tiger's Eye
SiO2 (Silicon Dioxide)
metamorphic
Milky Quartz
Silicon dioxide (SiO2)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
Kyanite (Purple variety)
Kyanite (Al₂SiO₅)
metamorphic
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Pegmatite with Black Tourmaline
Granitic Pegmatite with Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
igneous
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, along with Calcite and Pyrite)
metamorphic
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
igneous
Staurolite
Staurolite (Fe2+2Al9Si4O23(OH))
metamorphic
Ruby in Zoisite (Anyolite)
Corundum var. Ruby in Zoisite (Al2O3 + (Ca2Al3(SiO4)3(OH)))
metamorphic
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Amethyst
Quartz (SiO2) with trace iron impurities
Mineral
Beryllonite
Beryllonite (NaBePO4)
mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide - SiO2)
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Moonstone
Orthoclase (Potassium aluminum silicate - KAlSi3O8)
mineral
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
sedimentary
Dalmatian Stone (often called Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)
igneous
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic