Anthropic Metallic Specimen

Pyrite-bearing metamorphic rock (likely schist or quartzite)

Mica/quartz-rich metamorphic matrix with pyrite (FeS₂), possibly chalcopyrite (CuFeS₂)

Specular Hematite

Specularite (Iron Oxide, Fe2O3)

Quartz with Pyrite

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Galena

Galena (lead sulfide, PbS)

Gold-bearing quartz fragment (probable native gold)

Native gold (Au) in quartz (SiO₂), identification uncertain from the photograph

Gold-bearing quartz in a dark host rock (possible gold-in-quartz specimen)

Quartz (SiO₂) with possible native gold (Au) in a fine-grained host; exact identification is uncertain from the photo

Iridescent chalcopyrite (“peacock ore”)

Chalcopyrite, CuFeS₂, commonly surface-oxidized to covellite and related copper sulfides

Likely raw chalcopyrite or bornite specimen

Chalcopyrite (CuFeS₂), possibly bornite (Cu₅FeS₄)

Gold-bearing Quartz Ore

Auriferous Quartz (SiO2 with Au)

Pyrite-bearing rock (likely pyrite in quartz or altered host rock)

Pyrite, FeS₂, intergrown with quartz and/or iron-rich matrix

Pyrite-bearing sulfide ore

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

Not a rock, mineral, or geological specimen

Galena with Pyrite

Lead Sulfide (PbS) associated with Iron Sulfide (FeS2)

Dark metallic-looking mineral specimen, possibly magnetite

Magnetite (Fe₃O₄), tentative identification

Silver (Morgan Dollar)

Native Silver (Ag) - 90% Silver, 10% Copper alloy

Native bismuth

Bismuth (Bi), commonly with a naturally oxidized surface

Gold Ore (in Quartz/Pyrite)

Native Gold (Au) with Quartz (SiO2) and Pyrite (FeS2)

Sunstone

Aventurine Feldspar (Plagioclase or Oligoclase)

Gold-bearing Quartz (Auriferous Quartz)

Quartz (SiO2) with native Gold (Au) inclusions

Epithermal Gold Ore (in Quartz/Rhyolite matrix)

Auriferous Quartz (Au + SiO2)

Nuummite

Orthoamphibole (mixture of Anthophyllite and Gedrite)

Auriferous Quartz with Pyrite

Gold-bearing Quartz (SiO2 + FeS2 + Au)

Tiger Iron / Banded Iron Formation

Banded Iron Formation (SiO2 with Fe2O3 and FeOOH)

Pyrite (Fool's Gold) in Matrix

Iron Disulfide (FeS2)

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Gold Ore

Native Gold (Au) in Matrix

Gold Ore in Quartz

Native Gold (Au) in Quartz (SiO2) matrix

Hypersthene

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

Native Gold in Quartz Host

Hydrothermal Gold (Au) in Quartz (SiO2)

Pyrite (fool’s gold)

Pyrite, FeS₂

Peacock ore (likely chalcopyrite)

Iridescent tarnished chalcopyrite, CuFeS₂; sometimes marketed as bornite, Cu₅FeS₄

Polished iron-rich meteorite (probable Sikhote-Alin-type iron meteorite)

Fe–Ni kamacite/taenite alloy, with possible troilite inclusions

Likely pyrite-bearing rock fragment

Pyrite, FeS₂, possibly in a dark host rock

Native gold-bearing quartz/rock fragment

Native gold (Au), likely in quartz or iron-oxide matrix

Banded iron formation fragment (ironstone)

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

Fluorite on Matrix

Calcium Fluoride (CaF2)

Metallic gray mineral specimen, possibly galena or metallic ore

Uncertain from photograph; galena (PbS) is a possibility, but iron sulfide or industrial metal slag cannot be excluded

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Gold-bearing quartz vein material (likely native gold with sulfides)

Native gold (Au), probably with quartz (SiO₂) and iron/copper sulfide minerals

Quartz with Pyrite and Lichen

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Pyrite in Matrix (Fool's Gold)

Iron Disulfide (FeS2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)