Anthropic Metallic Specimen

Iridescent bismuth crystal

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

Iridescent bismuth crystal

Bismuth (Bi), artificially crystallized

Gold-bearing quartz (quartz with visible native gold)

Quartz (SiO₂) with native gold (Au)

Copper-bearing rock, likely native copper in a weathered matrix

Native copper (Cu), tentatively with copper sulfide/oxide minerals

Tumbled Sunstone

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

Iron-rich meteorite candidate

Unclassified stony-iron or iron meteorite fragment

Basalt River Stone

Basalt (Mafic volcanic rock)

Peacock Ore (Bornite or Chalcopyrite)

Bornite (Cu5FeS4) or Acid-Washed Chalcopyrite (CuFeS2)

Unidentified metallic mineral or metal-like specimen

Indeterminate from image; possibly galena (PbS) or a metallic sulfide

Polished tiger iron

Tiger iron; interbanded jasper, hematite, and crocidolite/quartz

Ironstone / limonite-rich concretion

Hydrated iron oxides, chiefly limonite/goethite (FeO(OH)·nH₂O), possibly with hematite

Pyrite

Iron Sulfide (FeS2)

Vesicular basalt (scoriaceous basalt) with secondary minerals

Basalt, predominantly plagioclase–pyroxene–olivine; surface cavities may contain zeolites or calcite

Ruby in Fuchsite (Composite/Stabilized)

Corundum (Al2O3) in Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Likely metallic sulfide mineral fragment

Possibly galena (PbS) or pyrite (FeS₂); identification is uncertain from the photograph

Polished metallic sulfide-bearing pebble

Likely pyrite-bearing slate, schist, or sulfide-rich ore; exact identification requires testing

Pyrite

Iron Sulfide (FeS2)

Gold Nugget Cluster

Native Gold (Au)

Dark metallic mineral specimen, possibly hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); exact identification requires testing

Pyrite in Matrix (often with Chalcopyrite)

Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)

Pyrite-rich Ore

Pyrite (FeS2) with secondary minerals

Milky Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Schist (specifically Mica Schist)

Mica Schist (primarily composed of Muscovite KAl2(AlSi3O10)(OH)2 and Biotite)

Pyrite-bearing rock (likely pyrite in a quartz-rich matrix)

Pyrite, FeS₂, with an unidentified host rock

Gold-bearing Quartz / Auriferous River Rock

Lode Gold in Quartz Matrix (SiO2 + Au)

Quartz with Pyrite inclusions

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)

Sunstone

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

Iron sulfide-rich ore, possibly pyrite-bearing gossan

Likely pyrite (FeS₂) with iron oxides/hydroxides and host rock; exact identification requires testing

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Pyrite-bearing quartz vein (likely pyrite ore)

Pyrite, FeS₂, with abundant quartz (SiO₂) and possibly chalcopyrite

Mixed Mineral Assortment (Pyrite, Kyanite, Agate, Jasper)

FeS2 (Pyrite), Al2SiO5 (Kyanite), SiO2 (Agate/Jasper)

Bismuth crystal

Bismuth (Bi), artificially crystallized

Copper-bearing rock, likely native copper in a matrix

Native copper (Cu), possibly with cuprite/malachite in a basaltic or porphyritic matrix

Pyrite

Iron Sulfide (FeS2)

Iron meteorite candidate

Probable iron-rich meteorite; possible stony-iron or weathered nickel–iron alloy

Purple fluorite cluster

Fluorite (calcium fluoride, CaF₂)

Iron-oxide-bearing rock fragment

Likely limonite/goethite with quartz or host-rock inclusions; exact identification requires testing

Tumbled dark pebble, likely hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); identification is uncertain from the image alone

Galena

Galena (lead sulfide, PbS)

Obsidian (likely snowflake-free black variety)

Volcanic glass; primarily SiO₂-rich rhyolitic composition

Limonite / Goethite (Ironstone)

Hydrated Iron(III) Oxide-Hydroxide FeO(OH)wnH2O

Banded iron formation (BIF) fragment

Metamorphosed iron formation; alternating hematite/magnetite and chert (SiO₂) layers