Bauxite
Bauxite (Al2O3·2H2O mixed with iron oxides)
sedimentary
Category
Igneous, Metamorphic, And Sedimentary (Mixed Assemblage)
Browse igneous, metamorphic, and sedimentary (mixed assemblage) specimens identified by the Rock Identifier community.
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Tumbled yellow-brown jasper
Jasper, microcrystalline quartz (SiO₂) with iron-oxide impurities
mineral
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Weathered granite pebble
Granite, predominantly quartz–feldspar–mica aggregate
igneous
Pink Granite
Felsic Plutonic Rock (Granite)
igneous
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)
Igneous
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Clear or Cloudy)
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Pyrite in Quartz
FeS2 (Iron Pyrite) with SiO2 (Quartz)
Mineral/Igneous/Hydrothermal
Milky Quartz or Moonstone
Silicon Dioxide (SiO2) or Potassium Aluminum Silicate (KAlSi3O8)
mineral
Tumbled jasper or chalcedony pebble
Microcrystalline quartz (SiO₂), likely jasper/chalcedony with iron-oxide staining
mineral
Mixed Tumbled Stones (Mostly Agate, Jasper, and Quartz)
Silicon Dioxide (SiO2)
sedimentary and metamorphic minerals
Milky Quartz
Silicon Dioxide (SiO2)
mineral
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Pink Granite
Granite (Felsic Plutonic Igneous Rock)
igneous
Quartz with Iron Staining
SiO2 with Fe oxide impurities
mineral
Quartz
SiO2 (Silicon Dioxide)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz
SiO2 (Silicon Dioxide)
mineral
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
mineral
Galena
Lead Sulfide (PbS)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Agate/Jasper pebble)
Silicon Dioxide (SiO2)
mineral
Feldspar
KAlSi3O8 - NaAlSi3O8 - CaAl2Si2O8 (Feldspar group)
mineral
Pyrite
Iron Pyrite (FeS2)
mineral
Pyrite (Fools Gold)
Iron Disulfide (FeS2)
mineral
Blue Apatite
Fluoroapatite (Ca5(PO4)3F)
mineral
Magnetite Orthorthotropic Rock
Magnetite (Fe3O4)
mineral
Pegmatite with Quartz and Feldspar
Intrusive Igneous Rock
igneous
Quartz-bearing granite or pegmatite fragment
Likely granitic material composed mainly of quartz (SiO₂), feldspar, and possibly biotite or hornblende
igneous
Rose Quartz
Silicon Dioxide (Quartz), SiO2
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
sedimentary (anthropogenic / man-made)