Anthropic Metallic Specimen

Tumbled metallic sulfide mineral specimen, likely pyrite-bearing ore

Likely pyrite (FeS₂) with associated sulfides and host rock; exact identification requires testing

Basalt

Mafic Igneous Rock

Lapis Lazuli (Low Grade)

Lapis Lazuli (Metamorphic rock containing lazurite, calcite, and pyrite)

Hypersthene

Enstatite-Ferrosilite series, (Mg,Fe)2Si2O6

Fluorite (Purple variety)

Calcium Fluoride (CaF2)

Pyrite

Iron Pyrite (FeS2)

Bornite

Cu5FeS4 (Copper Iron Sulfide)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Silver-colored mica schist

Muscovite–quartz schist, possibly with biotite

Pyrite

Iron Disulfide (FeS2)

Tumbled rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Pyrite-bearing quartz vein rock

Pyrite (FeS₂) in quartz, possibly with iron-oxide weathering products

Weathered iron-rich mineral concretion

Likely limonite/goethite concretion (hydrated iron oxides), possibly a weathered ironstone fragment

Native gold-bearing quartz vein specimen

Native gold (Au) in quartz, with possible iron-oxide and sulfide minerals

Sunstone (Oregon Sunstone)

Labradorite (Feldspar variety) - (Ca, Na)(Al, Si)4O8

Milky quartz

Quartz (silicon dioxide, SiO₂)

Likely galena-bearing ore

Galena (PbS), possibly with sphalerite or other sulfides

Basalt

Basalt (extrusive volcanic rock)

Basalt

Basalt (composition of plagioclase feldspar, pyroxene, and olivine)

Basalt Pebble

Basalt (Extrusive Mafic Igneous)

Native gold nuggets (likely gold-bearing specimen)

Native gold, Au; possibly associated quartz or sulfide matrix

Milky quartz

Quartz (silicon dioxide, SiO₂)

Hematite

Iron(III) oxide (Fe2O3)

Gold-bearing quartz or iron-stained quartzite

Quartz (SiO₂), possibly with pyrite or native gold inclusions

Native gold-bearing rock (probable gold nugget/ore fragment)

Native gold, Au, associated with quartz and/or iron oxides

Likely weathered basalt or dark volcanic rock

Basalt; primarily plagioclase feldspar and pyroxene, with possible olivine and iron oxides

Gneissic Schist

Gneiss-schist (Metamorphic rock)

Basalt

Aphanitic Mafic Igneous Rock

Pyrite in Matrix (Fool's Gold)

Iron Sulfide (FeS2)

N/A - Man-made object (Jewelry Chain)

Antiqued or Oxidized Metal Chain (often Steel or Brass)

Pyrite-bearing rock, likely pyrite quartzite or sulfide ore

Pyrite (FeS₂), possibly with quartz and minor iron sulfides

Fluorite on Host Rock

Calcium Fluoride (CaF2)

Silver (Native Silver)

Native Silver (Ag)

Serpentinite (likely)

Serpentinite, composed mainly of serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible magnetite, chromite, and talc

Weathered dark mineral/rock fragment

Indeterminate; possibly iron-rich basalt, slag, or a sulfide-bearing mineral

Basalt River Stone

Basalt

Banded iron formation (ironstone), likely hematite–magnetite-rich

Banded iron formation (BIF), composed chiefly of hematite (Fe₂O₃), magnetite (Fe₃O₄), and microcrystalline quartz (SiO₂)

Garnet Schist

Almandine Garnet in Micaceous Schist

Peacock ore (iridescent chalcopyrite)

Chalcopyrite, CuFeS₂, commonly surface-treated to enhance iridescence

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Gold-bearing sulfide ore, likely gossan or quartz-vein material

Native gold (Au) with probable iron oxides/hydroxides and sulfides, possibly quartz matrix