Gneiss
Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)
metamorphic
Category
Mineral Precipitate (Anthropogenic Context)
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Learn about Mineral Precipitate (Anthropogenic Context) in the encyclopedia
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Granite
Granite (Felsic Plutonic Rock)
igneous
Green Fluorite
Calcium Fluoride (CaF2)
mineral
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
Fluorite Carving
Fluorite (Calcium Fluoride, CaF2)
mineral
Sandstone
Arenite
sedimentary
Sandstone (with banding)
Arenite (primarily SiO2)
sedimentary
Native Copper (Penny specimen)
Native Copper (Cu)
mineral
Cubic Zirconia (Faceted)
Zirconium dioxide (ZrO2)
mineral
Sandstone
Arenite (SiO2 dominant)
sedimentary
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Bauxite
Bauxite (mainly Al(OH)3, AlO(OH))
sedimentary
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Greenstone
Greenschist (metamorphosed mafic igneous rock)
metamorphic
Eclogite
Eclogite (Omphacite + Pyrope)
metamorphic
Gold Ore in Quartz
Native Gold (Au) in Quartz (SiO2)
mineral
Staurolite (Fairy Stone)
Staurolite (formula: Fe2+2Al9Si4O23(OH))
metamorphic
Okenite (in Zeolite matrix)
Okenite (CaSi2O5 · 2H2O)
mineral
White Quartz with Black Tourmaline
Silicon Dioxide (SiO2) with Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
mineral
Quartz (with probable host rock)
Silicon Dioxide (SiO2)
mineral
Bauxite
Bauxite (Al2O3·nH2O)
sedimentary
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
igneous
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Bauxite
Bauxite (Al2O3·nH2O)
sedimentary
Limonite-stained Quartz
Silicon Dioxide (SiO2) with Iron Oxide/Hydroxide (FeO(OH)·nH2O) staining
mineral
Limonite
Limonite (FeOO·nH2O)
mineral
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Banded Gneiss (River Cobble)
Gneiss (a high-grade metamorphic rock)
metamorphic
Orpiment
Orpiment (As2S3)
mineral
Gold Ore in Matrix
Native Gold (Au) in Quartz/Host Rock
mineral
Gold-bearing Quartz Ore
Auriferous Quartz (SiO2 with Au)
mineral
Lapis Lazuli
Sodalite-rich metamorphic rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2
metamorphic
Chrysocolla in Matrix
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
mineral
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite treated with acid
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Peacock Ore (Bornite/Chalcopyrite)
Bornite (Cu5FeS4) or Chalcopyrite (CuFeS2)
mineral
Amygdaloidal Basalt
Basalt with Secondary Mineral Infillings
igneous
Diorite (River Cobble)
Phaneritic intermediate plutonic rock
igneous
Chrysocolla on Quartz with Iron Oxides
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
mineral