Bauxite
Bauxite (Al(OH)3, γ-AlO(OH), and α-AlO(OH))
sedimentary
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
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Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
River Rock (Basalt/Greywacke pebbles)
Fluvial gravel primarily composed of Mafic Volcanic Rock (Basalt) or Lithic Sandstone (Greywacke)
igneous and sedimentary
Pyrite in Host Rock
Iron Disulfide (FeS2)
mineral
Pink Granite
Phaneritic Felsic Igneous Rock (Granite)
igneous
Seashell fragment
Calcium carbonate (CaCO3)
Biogenic material
Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Pink Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
mineral
Amethyst (Faceted)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
mineral
Weathered iron-rich rock, possibly laterite or ironstone
Goethite–hematite-rich ferruginous rock; uncertain without testing
sedimentary
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Mineral (Organic Gemstone)
Bauxite
AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)
sedimentary
Quartz (specifically Milky or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Chert
Chert (Microcrystalline Quartz)
sedimentary
Small quartz-rich rock fragment (tentative)
Quartz, silicon dioxide (SiO₂), possibly in a feldspar-bearing granite fragment
mineral
Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Lapis Lazuli (Tumbled Stone)
Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (Lazulite-rich Metamorphic Rock)
metamorphic
Limestone
Sedimentary Rock (Primarily Calcium Carbonate, CaCO3)
sedimentary
Weathered quartz-rich pebble
Quartzite or silicified sandstone; predominantly microcrystalline quartz (SiO₂)
metamorphic
Lapis Lazuli (Tumbled Specimen)
Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)
metamorphic
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Pumice
Pumice (Vesicular volcanic glass)
Igneous
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O
mineral
Bauxite
Bauxite (Al(OH)3, AlO(OH))
sedimentary
Bauxite
Bauxite (Al(OH)3, AlO(OH))
sedimentary
Bauxite
Aluminium ore (Hydrated aluminium oxides AlOx(OH)3-2x)
sedimentary
Coal (Bituminous Coal)
Caustobiolith / Sedimentary Rock
sedimentary
Goldstone (aventurine glass)
Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone
gemstone
Terracotta (Man-made ceramic brick fragment)
Baked clay / High-iron ceramic (Silicate-based ceramic)
Anthropogenic material (Man-made sedimentary mimic)
Desert Rose (Gypsum Rose)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Exposed aggregate concrete (stone-chip surface)
Portland-cement concrete containing natural aggregate; not a natural rock
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Weathered limestone
Calcite-rich carbonate rock (mostly CaCO₃)
sedimentary
Potassium Feldspar
Orthoclase (KAlSi3O8)
mineral
Chert (Flint)
Silicon dioxide (SiO2)
sedimentary
Faceted Gemstone
Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass
gemstone
Red Granite
Phaneritic Plutonic Rock (High Potassium Feldspar)
igneous
Sandstone
Arenite
sedimentary
Sapphire
Corundum (Al2O3)
gemstone
Amethyst
SiO2 (Silicon Dioxide with Iron impurities and natural radiation influence)
mineral