Small rough quartz-family crystal specimens, including likely amethyst and citrine
Quartz, silicon dioxide (SiO₂); purple specimen is likely amethyst, yellow specimen likely citrine or iron-stained quartz
mineral
Category
Mineral Based Alloy (Anthropogenic)
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
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Gold Nugget
Gold (Au)
mineral
Native Gold Flake
Gold (Au)
mineral
Fossilized Shark Tooth
Selachimorpha fossil
fossil
Granite
Phaneritic plutonic rock (Quartz, Feldspar, Mica)
igneous
Fossilized Crab Carapace (Concretion)
Decapoda (fossil), typically preserved in calcite or siderite concretion
sedimentary
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Chalcopyrite
Copper Iron Sulfide (CuFeS2)
mineral
River Cobble (Phyllite or Quartzite)
Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)
metamorphic
Dalmatian Jasper
Peralkaline Quartz-Feldspar Igneous Rock with Arfvedsonite
igneous
Possible metallic meteorite or iron-nickel bead
Unconfirmed; possible Fe–Ni alloy (kamacite/taenite)
meteorite
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
metamorphic
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Tumbled Carnelian and Quartz Mix
Silicon Dioxide (SiO2) with iron oxide impurities
mineral
Diamond
Native Carbon (C)
mineral
Gold Nugget
Native Gold (Au)
mineral
Gold Nugget
Native Gold (Au)
mineral
Silver (Jewelry Specimen)
Native Silver (Chemical Formula: Ag)
mineral
Asphalt / Road Aggregate
Bituminous Conglomerate (synthetic)
sedimentary
Copper-bearing volcanic breccia
Altered andesite or rhyolite breccia with secondary copper minerals, likely chrysocolla and/or malachite
igneous
Amethyst
Amethyst (Silicon Dioxide with iron impurities), SiO2
mineral
Chevron amethyst point
Quartz, SiO₂, with purple amethyst and white quartz zoning
gemstone
Gold Nugget
Native Gold (Au)
mineral
Mica Schist
Mica Schist
metamorphic
Chrysocolla
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
mineral
Native copper nugget
Copper (Cu), often with cuprite or copper-oxide surface
mineral
Raw pale-green beryl (likely aquamarine)
Beryl, Be₃Al₂Si₆O₁₈; blue-green variety is aquamarine
mineral
Copper Nugget
Native Copper (Cu)
mineral
Galena (lead sulfide)
Galena, PbS
mineral
Silicon
Element Si
mineral
Bismuth Crystal
Bismuth (Bi)
mineral
Peacock Ore
Bornite (Cu5FeS4) or Chalcopyrite treated with acid
mineral
Tumbled amethyst (tentative)
Amethyst, purple variety of quartz (SiO₂)
mineral
Chalcopyrite on Quartz
Copper Iron Sulfide (CuFeS2)
mineral
Fossilized Brachiopod
Brachiopoda (e.g., Rhynchonellida or Spiriferida)
sedimentary
Soapstone (talc-rich schist)
Talc schist; chiefly hydrated magnesium silicate, Mg₃Si₄O₁₀(OH)₂
metamorphic
Wallboard/Drywall (Gypsum-based)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
sedimentary
Polished turquoise
Turquoise — hydrated copper–aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
gemstone
Aquamarine
Beryllium aluminum silicate (Be3Al2Si6O18)
mineral
Metallic meteorite fragment (probable stony-iron or iron meteorite)
Undetermined meteoritic Fe–Ni alloy with silicate minerals
meteorite
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Shark Tooth Fossil
Chondrichthyes (shark) tooth
fossil