Amethyst Quartz Pebble
Silicon Dioxide (SiO2) with iron impurities
mineral
Category
Mineral Precipitate (Anthropogenic Context)
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Copper Ore with Chrysocolla and Azurite
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / Cu3(CO3)2(OH)2 (Azurite)
mineral
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Gold Ore in Quartz
Auriferous Quartz (Gold: Au; Quartz: SiO2)
Mineral
Rose Quartz
Crystalline Silicon Dioxide with trace Titanium/Manganese/Iron (SiO2)
mineral
Labradorite
Labradorite, (Ca, Na)(Al, Si)4O8
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
mineral
Black Tourmaline in Quartz
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) in Silicon Dioxide (SiO2)
igneous
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Gold Nugget
Native Gold (Au)
mineral
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
metamorphic
Citrine (likely Heat-Treated Amethyst)
Silicon Dioxide (SiO2)
mineral
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
mineral
Howlite and Purpurite druzy
Calcium Borosilicate Hydroxide (Howlite) and Manganese Phosphate (Purpurite)
mineral
Tumbled Moonstone
Feldspar (Orthoclase/Albite), KAlSi3O8
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Satin Spar (often sold as Selenite)
Gypsum (CaSO4·2H2O)
mineral
Sandstone
Arenite (SiO2 primarily)
sedimentary
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18
mineral
Sodalite
Na8(Al6Si6O24)Cl2
mineral
Granite
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8, and Mica)
Igneous
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
sedimentary
Green Aventurine
Quartz with Fuchsine inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
mineral
Granite
Phaneritic Igneous Rock (Granite)
igneous
Chrysocolla
Chrysocolla, (Cu, Al)2H2Si2O5(OH)4·nH2O
mineral
Vesicular Basalt (Iron-rich)
Scoriaceous Basalt / Oxidized Vesicular Basalt
igneous
Garnet Beads
Garnet Group (complex nesosilicates, e.g., Almandine Fe3Al2(SiO4)3)
Mineral
Corundum
Corundum (Aluminium oxide, Al2O3)
mineral
Granite Cobble
Granite
igneous
Basalt with Quartz/Feldspar Vein
Amygdaloidal Basalt with Plutonic intrusion (SiO2/KAlSi3O8)
igneous
Milky Quartz with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Disulfide (FeS2)
mineral
Granite
Granite (Felsic intrusive igneous rock)
igneous
Charoite
Charoite (Hydrated potassium, sodium, calcium, barium, strontium silicate hydroxide fluoride)
metamorphic
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
metamorphic
Gneiss
Gneiss
metamorphic
Greenstone
Metabasalt / Greenschist facies rock
metamorphic
Granite Pebble
Granite (Phaneritic intrusive igneous rock)
igneous
Granite (Pink/Red)
Phaneritic Plutonic Felsic Rock (major minerals: Quartz, Orthoclase Feldspar, Plagioclase Feldspar)
igneous
Gneiss (Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Mica/Amphibole)
metamorphic