Mineral (Refined Metal)

Native Copper

Copper (Cu)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Granite

Felsic intrusive igneous rock

Lapis lazuli bead bracelet

Lapis lazuli, chiefly lazurite (Na₃Ca(Si₃Al₃)O₁₂S); commonly with calcite and pyrite

Goethite / Limonite Gossan

Hydrated Iron Oxide (FeO(OH))

Native gold (gold nugget)

Native gold, Au; commonly alloyed with silver and copper

Quartz vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Lithic Matrix

Opalite (Man-made Glass)

Synthetic Opalised Glass

Blue-green faceted pendant stone

Undetermined; possibly synthetic glass or a blue-green gemstone such as topaz or quartz

Quartz vein in dark host rock

Milky quartz (SiO₂) in an unidentified dark metamorphic host, possibly amphibolite or schist

Granite

Granite (felsic intrusive igneous rock)

Indeterminate metallic mineral fragments

Possibly pyrite, chalcopyrite, or metallic sulfide-bearing rock

Pyrite

Iron Sulfide (FeS2)

Blue glass-like bead or gemstone keychain ornament

Indeterminate; likely cobalt-blue glass or synthetic blue spinel, not identifiable as a natural mineral from the image

Orange Calcite with Siderite/Iron Oxide Coating

Calcium Carbonate (CaCO3)

Rhodochrosite (Beads) and Citrine (Pendant)

Rhodochrosite (MnCO3) and Quartz variety Citrine (SiO2)

Iron-stained quartz-bearing rock (probable weathered quartz vein or ironstone)

Quartz (SiO₂) with goethite/limonite iron oxides; possibly altered volcanic or metamorphic host rock

Black-and-white agate geode pendant

Agate (microcrystalline quartz, SiO₂), likely a hollow geode slice with chalcedony and drusy quartz

Native Silver Nugget

Silver (Ag)

Granite

Intrusive igneous rock

Pyrite (on a metal substrate)

Iron Sulfide (FeS2)

Pink faceted gemstone, likely amethyst or pink quartz

Quartz (SiO₂), likely pale amethyst; exact identification requires testing

Native Copper

Native Copper (Cu)

Quartz-rich pegmatite with mica

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and muscovite/biotite mica

Gold Nugget

Gold (Au)

Black tourmaline pendant

Schorl, a sodium–iron tourmaline; approximate formula NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Diamond (set in jewelry)

Diamond (Carbon, C)

Diamond (in a gold ring)

Diamond (pure carbon, C)

Quartz Vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Igneous/Metamorphic Matrix

Quartz Vein in Sedimentary Matrix

Silicon Dioxide (SiO2) with host rock

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in matrix

Limonite and Goethite encrusted Quartz (Iron-stained Gossan)

FeO(OH)·nH2O (Limonite) / FeO(OH) (Goethite) on SiO2 (Quartz)

Fossil bone or tooth fragment

Mineralized fossil vertebrate bone/tooth; exact taxon cannot be determined from the photograph

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within metamorphic/igneous matrix

Pink Granite

Granite (Phaneritic Quartz-Feldspar rock)

Gold Ore in Quartz

Auriferous Quartz (Au + SiO2)

Bismuth Crystal

Bismuth (element symbol Bi, atomic number 83)

Likely weathered metallic mineral or slag fragment

Indeterminate; possibly iron-rich sulfide/oxide material or industrial slag

Opalite

Synthetic Opalite Glass / Opalized Glass

Opalite crescent pendant

Opalite (man-made opalescent glass; not a natural mineral)

Limonite and Goethite on Gossan

FeO(OH)·nH2O

Quartz Vein in Host Rock (Gabbro or Basalt)

Silicon Dioxide (SiO2) with Mafic Silicates