Anthropic Metallic Specimen

Sunstone

Plagioclase Feldspar (Na,Ca)(Al,Si)4O8

Pyrite-bearing rock (iron pyrite)

Pyrite, FeS₂, likely disseminated or massive in a host rock

Magnetite-rich ironstone (probable magnetite ore)

Magnetite, Fe₃O₄, likely in a fine-grained ironstone matrix

Gold Nugget (Placer Gold)

Native Gold (Au)

Opalite

Synthetic Opalite Glass (Silicon Dioxide)

Galena (lead sulfide)

Galena, PbS

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Weathered metallic meteorite (probable iron meteorite)

Fe–Ni alloy, mainly kamacite and taenite; exact classification requires chemical and petrographic testing

Pyrite

Iron disulfide (FeS₂), commonly called fool’s gold

Native Gold Nugget

Gold (Au)

Pyrite (Iron Pyrite) with Goethite Oxidation

Iron Sulfide (FeS2)

Gold-bearing quartz and sulfide-bearing rock fragments

Native gold (Au) associated with quartz (SiO₂) and likely iron sulfides, possibly pyrite

Basalt pebble

Basalt

Basalt

Mafic volcanic rock

Magnetite-rich iron ore

Magnetite (Fe₃O₄), possibly mixed with hematite or metallic sulfides

Limonite (Ironstone Concretion)

Hydrous ferric oxides (FeO(OH)·nH2O)

Metallic sulfide-bearing metamorphic rock

Likely graphitic schist or sulfide-rich schist, with possible pyrite/arsenopyrite and mica

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Likely ironstone pebble

Iron-oxide-rich concretion, composed mainly of goethite and/or hematite

Pyrite-bearing rock (likely pyrite-rich shale or matrix specimen)

Pyrite (FeS₂) in a fine-grained host rock; host is uncertain from the image

Native Silver Nugget

Silver (Ag)

Quartz with Schorl inclusions

Silicon Dioxide (SiO2) with Sodium Iron Aluminum Borosilicate Hydroxide (Black Tourmaline)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Weathered brown stone, likely basalt or iron-stained volcanic rock

Indeterminate; possibly vesicular basalt (mafic silicate rock)

Sunstone

Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Galena-bearing sulfide ore

Galena (lead sulfide, PbS), possibly with sphalerite and/or pyrite

Placer Gold Nugget

Native Gold (Au)

Polished pyrite nodule (likely)

Pyrite, FeS₂

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly mixed with chalcopyrite or other iron sulfides

Probable weathered sulfide-bearing rock

Indeterminate; possibly pyrite- or chalcopyrite-bearing matrix

Pyrite

Iron Sulfide (FeS2)

Milky Quartz with Mica (Gneiss/Schist influence)

Silicon Dioxide (SiO2) with Phyllosilicates

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Muscovite Schist with Quartz

KAl2(AlSi3O10)(OH,F)2 (Muscovite) in Schist

Milky Quartz with Dendritic Inclusions

Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions

Fossilized tooth or jaw fragment (likely fish or reptile)

Indeterminate vertebrate bone/tooth; mineralized hydroxyapatite, commonly Ca₅(PO₄)₃(OH)

Sunstone

Plagioclase feldspar (with Copper or Hematite inclusions)