Anthropic Metallic Specimen

Likely metallic mineral specimens

Probably native iron or iron oxide/hydroxide material; exact identification requires testing

Bornite (Peacock Ore)

Bornite (Cu5FeS4)

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Aura Quartz (Coated Quartz)

Silicon Dioxide (SiO2) coated with vaporized metals

Banded iron formation (ironstone)

Banded iron formation, chiefly hematite/magnetite with chert (SiO₂)

Iron Meteorite (Campo del Cielo)

Iron Meteorite, Group IAB (FeNi Alloy: Kamacite and Taenite)

Pyrite (likely)

Iron disulfide, FeS₂; commonly called “fool’s gold”

Weathered metallic sulfide-bearing rock, possibly chalcopyrite ore

Likely chalcopyrite (CuFeS₂) in a weathered host rock; identification is uncertain from the photograph

Pyrite in Quartz Matrix

Iron Disulfide (FeS2) in Silicon Dioxide (SiO2)

Specular Hematite and Magnetite Ore

Iron Oxide (Fe2O3 and Fe3O4)

Likely silver-gray metallic ore fragment

Unidentified metallic mineral; possibly galena (PbS), but the image is insufficient for a confident identification

Silver (Native Silver/Alloy Specimen)

Ag (Native Silver element), specifically a 90% Ag / 10% Cu alloy

Tumbled metallic sulfide specimen, likely galena

Galena (lead sulfide, PbS), possibly mixed with pyrite or other sulfides

Gold Nugget

Native Gold (Au)

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxide-coated

Pyrite (likely)

Iron disulfide, FeS₂; commonly called fool’s gold

Quartz with Chalcopyrite and Pyrite

Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)

Metallic sulfide-bearing pebble, likely pyrite in quartz or host rock

Probable pyrite (FeS₂), possibly with chalcopyrite (CuFeS₂) in a quartz-rich matrix

Likely galena

Galena (lead sulfide, PbS)

Weathered sulfide-bearing ore specimen

Likely pyrite- and/or chalcopyrite-bearing quartz–iron-oxide rock; exact identification requires testing

Native gold nugget

Gold (Au), commonly with minor silver or copper

Native copper-bearing rock (probable copper ore)

Native copper (Cu), likely with copper sulfide/oxide minerals in a host rock

Hematite

Iron (III) Oxide, Fe2O3

Magnetite / Hematite (Iron Ore Pebble)

Fe3O4 (Magnetite) / Fe2O3 (Hematite)

Silver (Jewelry Specimen)

Native Silver (Ag)

Pyrite in Quartz

Iron Sulfide (FeS2) embedded in Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Native Copper in Basalt

Cu-element in Mafic Volcanic Rock (Basalt)

Chalcopyrite in Gossan

Chalcopyrite (CuFeS2) in a Limonite-rich Gossan matrix

Basalt River Pebble (with possible Pyrite/Mineralization)

Basalt (Mafic volcanic rock)

Pyrite-bearing metamorphic rock (likely schist or gneiss)

Pyrite (FeS₂) in a quartz–mica-rich host rock

Pyrite in Matrix

Iron Sulfide (FeS2)

Copper-bearing rock, likely native copper in matrix

Native copper (Cu), possibly with cuprite/iron-rich matrix

Gold Grain

Native Gold (Au)

Hypersthene

Enstatite (Hypersthene variety), (Mg,Fe)SiO3

Likely pyrite-bearing metamorphic rock

Quartz–mica schist or phyllite with disseminated pyrite (FeS₂)

Blue Goldstone

Man-made glass with cobalt and metal flecks

Galena

Galena (lead sulfide, PbS)

Magnetite Nodule

Magnetite (Fe3O4)

Gold in Quartz Matrix

Native Gold (Au) with Quartz (SiO2)

Banded iron formation (iron-rich jasper/chert)

Banded iron formation, chiefly quartz (SiO₂) with hematite, magnetite, and/or goethite (Fe oxides/hydroxides)

Silver Nuggets (Natural or Cast)

Native Silver (Ag)