Quartzite
Metamorphosed Quartz Sandstone (SiO2)
metamorphic
Category
Crystal
Browse crystal specimens identified by the Rock Identifier community.
Nephrite Jade
Tremolite-Actinolite solid solution Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Quartz in Limonite-rich Matrix
Silicon Dioxide (SiO2) with Goethite/Limonite FeO(OH)·nH2O
Mineral in Sedimentary/Secondary host
Gabbro
Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)
igneous
Yellow Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
sedimentary
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
metamorphic
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
Smoky Quartz
Smoky Quartz (SiO2)
mineral
Blue Quartz (Blue Aventurine)
Silicon Dioxide (SiO2) with inclusions (typically crocidolite or dumortierite)
mineral
Green Aventurine
Quartz (Silicon Dioxide) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
Yellow Quartz (Citrine Quartzite)
Silicon Dioxide (SiO2)
metamorphic
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
mineral
Selenite (Gypsum)
Hydrous calcium sulfate (CaSO4·2H2O)
mineral
Sulfur (in host rock)
Native Sulfur (S8)
mineral
Diamond
Diamond (C)
mineral
Granite
Granite (Felsic Plutonic Rock)
igneous
Porphyry
Porphyritic Basalt/Andesite
igneous
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)
igneous
Citrine
Silicon Dioxide (SiO2)
mineral
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
mineral
Green Aventurine
Aventurine Quartz (SiO2) with Fuchsite inclusions
metamorphic
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Magnetite / Iron Ore
Magnetite (Fe3O4)
mineral
Copper Ore (with Malachite and Azurite)
Hydroxide copper carbonate (Cu2CO3(OH)2 / Cu3(CO3)2(OH)2)
mineral
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Pink Tourmaline in Quartz Matrix
Elbaite (Na(Li,Al)3Al6(Si6O18)(BO3)3(OH)4) in Quartz (SiO2)
mineral
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Granite
Phaneritic Plutonic Rock (Granite)
igneous
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Pallasite Meteorite
Pallasite (Iron-Nickel Matrix with Olivine/Peridot inclusions)
Mineral / Extraterrestrial Rock
Kidney Stone (Renal Calculus)
Calcium oxalate monohydrate (Whewellite) / CaC2O4·H2O
mineral
Snowflake Obsidian
Volcanic glass containing Cristobalite (SiO2)
igneous
Amethyst (Faceted Gemstone)
Silicon Dioxide (SiO2) with iron impurities
mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Rhyolite (Porphyritic)
Rhyolite (Felsic Extrusive Igneous Rock)
igneous
Garnet-Mica Schist
Schist (variety with Almandine Garnet, Fe3Al2(SiO4)3)
metamorphic
Basalt
Extrusive Mafic Igneous Rock
igneous
Porphyritic Basalt (Chinese Writing Stone/Flower Stone)
Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)
igneous
Rutilated Quartz
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
mineral