Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Category
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)
Weathered polymictic conglomerate or breccia
Polymictic conglomerate/breccia, likely iron-stained and quartz-bearing
Jasper pebble (possibly Red Jasper or Lake Superior Agate/Jasper mix)
Silicon Dioxide (SiO2) with Hematite inclusions
Mixed rock fragments, likely granite and weathered metamorphic rock
Granite (quartz–feldspar–mica aggregate) with probable schist/gneiss fragments
Weathered quartzite cobble
Quartzite, predominantly crystalline SiO₂
Tumbled hematite (likely hematite-rich iron oxide)
Hematite, Fe₂O₃; possibly mixed with magnetite, Fe₃O₄
Polished red jasper with quartz/chalcedony
Jasper (microcrystalline quartz, SiO₂), locally mixed with chalcedony or quartz
Red Jasper (in Quartz/Chalcedony)
Silicon Dioxide (SiO2) with iron oxide inclusions
Copper-stained quartz/igneous rock specimen
Quartz (SiO₂), with secondary copper minerals; host likely altered volcanic rock
Metallic sulfide mineral specimen, likely pyrite
Pyrite (FeS₂), possibly a pyrite-rich sulfide aggregate
Milky quartz
Quartz, silicon dioxide (SiO₂)
Pyrite-bearing sulfide specimen
Pyrite (FeS₂), possibly with chalcopyrite (CuFeS₂) and/or marcasite
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Hematite-rich ironstone concretion
Hematite (Fe₂O₃), likely mixed with goethite/limonite and silica
Iron-rich ochre (red/brown hematite pigment)
Hematite, Fe₂O₃, likely mixed with clay and quartz grains
Granite Pebble with Quartz/Feldspar Vein
Intrusive Felsic Igneous Rock (Granite)
Concrete with Exposed Aggregate
Anthropogenic conglomerate (Concrete)
Tumbled labradorite beads
Labradorite, a calcium-rich plagioclase feldspar (approximately (Ca,Na)(Al,Si)₄O₈)
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Mixed rounded river pebbles, probably quartz-rich metamorphic and volcanic rocks
Predominantly quartzite/metachert, with possible rhyolite, sandstone, and iron-stained quartz; exact species cannot be determined confidently from the image
Likely granite or granitic gneiss
Coarse-grained quartz–feldspar–mica rock; possibly biotite granite or banded granitic gneiss
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
Granite
Granite (composed of quartz, potassium feldspar, plagioclase, and mica/biotite)
Epidosite (Epidote-rich rock)
Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite)
Tumbled green jasper (probable serpentine-rich stone)
Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite
Yellow-brown jasper or silicified volcanic rock
Microcrystalline quartz (chalcedony), SiO₂, likely jasper
Magnetite-rich black sand
Magnetite (Fe₃O₄), likely mixed with other heavy minerals
Metallic sulfide mineral specimen, likely pyrite
Pyrite (FeS₂), possibly mixed with marcasite or another iron sulfide
Pyrite-bearing sulfide ore (likely pyrite with iron oxides)
Pyrite, FeS₂, possibly mixed with limonite/goethite and other sulfides
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Small rounded quartz-rich pebble
Likely quartz (SiO₂), possibly iron-stained or mixed with other minerals
Magnetite sand (black iron-oxide sand)
Magnetite, Fe₃O₄; commonly mixed with ilmenite and other heavy minerals
Tumbled pastel gemstone bead strand
Likely dyed or heat-treated quartz/chalcedony varieties, possibly rose quartz, amethyst, and agate
Tumbled jasper and agate assortment
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and other mineral impurities
Iron-rich sulfide ore, likely pyrite-bearing gossan
Pyrite (FeS₂), possibly mixed with iron oxides/hydroxides and other sulfides
Botryoidal limonite/goethite nodule
Limonite (largely goethite, FeO(OH), with hydrated iron oxides)
Natural gemstone and mineral collection
Mixed specimens, including turquoise, tiger’s eye, amethyst, fluorite, pyrite, garnet, rose quartz, lapis lazuli, obsidian, rhodonite, red corundum, labradorite, calcite, lepidolite, sodalite, apatite, and others
Amazonite (likely mixed with other feldspars/minerals)
Amazonite is a variety of Microcline, which is a tectosilicate mineral, formula KAISi3O8. The mixed beads could include other feldspars or quartz.
Metallic sulfide ore, possibly pyrite-rich
Pyrite (FeS₂), potentially mixed with chalcopyrite, galena, or iron oxides
Metallic sulfide mineral specimen, likely pyrite
Pyrite (iron disulfide, FeS₂), possibly mixed with marcasite or chalcopyrite