Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
Category
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
Hematite (Concretion)
Iron(III) oxide (Fe2O3)
Orthoclase Feldspar (Twinning Specimen)
Orthoclase (KAlSi3O8)
Gneiss (specifically a Granitic Gneiss specimen)
Gneiss (high-grade metamorphic rock primarily composed of Quartz, Feldspar, and Biotite/Amphibole)
Heat-Treated Amethyst (Commercial Citrine)
Silicon Dioxide (SiO2) - Macro-crystalline Quartz
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Biotite Schist
Biotite Schist
Blue Topaz
Aluminum Silicate Fluoride Hydroxide Al2SiO4(F,OH)2
Sandstone
Arenite (SiO2 primarily)
Quartz-bearing Ore (likely Gold-bearing Quartz)
Quartz (SiO2) with potential sulfide mineralization (Pyrite/Arsenopyrite)
Sandstone
Arenite (primarily Quartz Arenite)
Lapis Lazuli
Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)
Chondrite Meteorite
Ordinary Chondrite (L or H type)
Schist
Schist (Crystalline metamorphic rock)
Rutilated Quartz
Silicon Dioxide (SiO2) with inclusions of Titanium Dioxide (TiO2)
Quartz with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Vesicular Basalt with Secondary Mineral Infill
Mafic Volcanic Rock (Basalt)
Red Sandstone
Arenite (Fe2O3 enriched)
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Sandstone (Ferruginous)
Arenite with Hematite cement (SiO2 + Fe2O3)
Jasper
Jasper (Silicon Dioxide, SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Limonite with Galena
FeO(OH)·nH2O (Limonite) and PbS (Galena)
Sandstone
Arenite
Lepidolite
Lepidolite [K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2]
Sandstone
Arenite (SiO2 based typically)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Sandstone
Arenite (primarily SiO2)
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Obsidian
Volcanic glass (SiO2-rich extrusive igneous rock)
Banded Iron Formation
Banded Iron Formation (BIF)
Apatite
Apatite Group (e.g., Fluorapatite Ca5(PO4)3F, Chlorapatite Ca5(PO4)3Cl, Hydroxylapatite Ca5(PO4)3(OH))
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Granite (River Cobble)
Granite (rich in feldspar, quartz, and biotite)
Granitic Pegmatite with Tourmaline
Granite (Feldspar/Quartz matrix) with Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)
Lepidolite Polished Point
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Malachite
Copper(II) carbonate hydroxide [Cu2CO3(OH)2]
Sandstone (with Iron Oxidation)
Arenite (SiO2 with Fe-oxides)
Sandstone
Arenite (primarily SiO2)
Banded Onyx (Mexican Onyx / Travertine)
Calcite (CaCO3) - Banded Travertine
Sandstone (Ferruginous)
Sandstone (Clastic sedimentary rock, predominantly SiO2 with Fe2O3 cement)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)