Blue Kyanite
Kyanite (Al2SiO5)
mineral
Category
Sedimentary (Processed Mineral Product)
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
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Botryoidal chalcedony (agate/geode fragment)
Chalcedony, microcrystalline SiO₂; likely quartz with minor iron-oxide and carbonate inclusions
mineral
Weathered basaltic rock
Basalt, likely altered basalt (plagioclase–pyroxene ± olivine; possible iron-oxide staining)
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Turquoise and Hematite
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Hematite: Fe2O3
mineral
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Blue-dyed magnesite beads (often sold as “turquoise howlite”)
Magnesite, MgCO₃; commonly dyed blue and possibly marketed as dyed howlite, Ca₂B₅SiO₉(OH)₅
mineral
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Mica Schist with Quartz
Mica Schist (KAl2(AlSi3O10)(OH)2 / SiO2)
metamorphic
Tumbled amethyst
Quartz, crystalline silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
mineral
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Granite
Granite (Felsic Intrusive)
igneous
Stichtite (often found in Serpentinite)
Stichtite Mg6Cr2CO3(OH)16·4H2O
Mineral
Milky Quartz Pebble with Iron Inclusions
Silicon Dioxide (SiO2)
mineral
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2) matrix
metamorphic
Sulfur on Aragonite
Sulfur (S) and Aragonite (CaCO3)
Mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Native bismuth
Bismuth (Bi), commonly with a naturally oxidized surface
mineral
Iron Slag (Industrial Byproduct)
Anthropogenic pyrometallurgical residue
mineral
Tumbled amethyst
Quartz, SiO₂; purple coloration from iron-related defects and irradiation
mineral
Gypsum rosette cluster (desert rose)
Gypsum, calcium sulfate dihydrate (CaSO₄·2H₂O), rosette habit
mineral
Blue slag glass / industrial smelter slag
Man-made iron-rich silicate slag; composition variable, commonly Fe–Ca–Mg–Al silicates with glassy phases
mineral
Iron-rich metamorphic rock, possibly micaceous schist
Biotite–quartz schist or iron-rich phyllite (tentative visual identification)
metamorphic
Possible industrial slag or basaltic volcanic glass
Likely iron-rich vitreous slag; natural alternative: basaltic glass (tachylite)
igneous
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Mixed gravelly conglomeratic road aggregate
Polymictic clast-supported conglomerate or fill; composition varies, commonly quartz, feldspar, basalt, and weathered rock fragments
sedimentary
Granite
Granitoid (dominated by Quartz and Feldspar)
igneous
Iron-rich weathered pebble (likely limonite/goethite-bearing rock)
Limonite mixture, commonly dominated by goethite (FeO(OH)) and hematite (Fe₂O₃)
mineral
Weathered iron-rich sandstone or ferruginous pebble
Quartz-rich sandstone with iron-oxide cement; exact identification requires testing
sedimentary
Zircon
Zirconium Silicate (ZrSiO₄)
mineral
Red Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Granite
Granite
igneous
Note: Item is not a geological specimen
Guitar Components (Steel, Nickel, Plastic, Wood)
Synthetic/Consumer Product
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Amethyst ring
Amethyst, purple quartz (SiO₂), likely set with diamond or other accent stones
gemstone
Black tourmaline beads (likely schorl)
Schorl, NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄
mineral
Quartz crystal pendant (likely smoky quartz or iron-stained quartz)
Quartz, silicon dioxide (SiO₂)
mineral
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Polished sodalite pendant
Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, likely with minor albite or nepheline
mineral