Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
igneous
Category
Mineral Precipitate (Anthropogenic Context)
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Limonite
Limonite (FeOO·nH2O)
mineral
Man-made Jewelry Charm (Enameled Metal)
Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.
Synthetic / Manufactured Artifact
Schist with Quartz Vein
Mica Schist with Crystalline Quartz (SiO2)
metamorphic
Chrysocolla in Matrix
Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Quartz (Milky/Rose variety)
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Mineral Inclusions
Quartz (Silicon Dioxide - SiO2)
mineral
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Chrysocolla on Quartz with Iron Oxides
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions (Limonite/Goethite)
mineral
Staurolite (Fairy Stone)
Staurolite (formula: Fe2+2Al9Si4O23(OH))
metamorphic
Okenite (in Zeolite matrix)
Okenite (CaSi2O5 · 2H2O)
mineral
Pegmatite (with smoky quartz and tourmaline/biotite)
Pegmatitic Granite
igneous
Sandstone or Quartzite
Arenite (if sedimentary) / Quartzite (if metamorphic)
Sedimentary or Metamorphic
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Chalcopyrite (Peacock Ore)
Chalcopyrite (CuFeS2)
mineral
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Bornite (Peacock Ore)
Bornite (Cu5FeS4)
mineral
Sandstone (likely Quartzose Sandstone pebble)
Arenite (primarily SiO2)
sedimentary
Obsidian (specifically Mahogany Obsidian)
Volcanic glass (high silica content, SiO2)
igneous
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
igneous
Sandstone
Arenite (SiO2 principal)
sedimentary
Lepidolite
K(Li,Al)3(Al,Si)4O10(F,OH)2 (Lithium-bearing phyllosilicate)
mineral
Sandstone
Arenite (SiO2 based)
sedimentary
Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
metamorphic
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
mineral
Gold-Bearing Quartz
Auriferous Quartz (SiO2 with native Au)
Mineral
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
igneous
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
igneous
Bauxite
Bauxite (mixture of hydrous aluminum oxides: Al(OH)3 & AlO(OH))
sedimentary
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Malachite
Copper carbonate hydroxide, Cu2CO3(OH)2
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Granodiorite (or Granite) Pebble
Phaneritic Felsic Igneous Pebble
igneous
Malachite
Malachite (Copper Carbonate Hydroxide, Cu2CO3(OH)2)
mineral
Gneiss
High-grade regional metamorphic rock (Foliated)
metamorphic
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Lapis Lazuli
Lapis Lazuli (Complex aggregate mainly of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Gneiss
Gneiss (a type of metamorphic rock)
Metamorphic Rock
Pegmatite with Schorl (Black Tourmaline) and Mica
Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)
igneous