Metal (Elemental Mineral)

Granite

Granite (felsic intrusive igneous rock)

Quartz vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Lithic Matrix

Bismuth crystal

Bismuth (Bi), commonly laboratory-grown hopper crystal

Polished banded agate, likely moss or dendritic agate

Microcrystalline quartz (chalcedony), SiO₂, with iron/manganese inclusions

Gold Nugget

Native Gold (Au)

Rhodochrosite (Beads) and Citrine (Pendant)

Rhodochrosite (MnCO3) and Quartz variety Citrine (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Zircon

Zircon (Zirconium Silicate - ZrSiO4)

Lepidolite

K(Li,Al)3(Al,Si,3O10)(F,OH)2

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Lepidolite

K(Li,Al)3(Al,Si,Rb,Cs)4O10(F,OH)2

Granite

Intrusive igneous rock

Quartz vein in dark host rock

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

Goethite / Limonite Gossan

Hydrated Iron Oxide (FeO(OH))

Orange Calcite with Siderite/Iron Oxide Coating

Calcium Carbonate (CaCO3)

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

Opalite (Man-made Glass)

Synthetic Opalised Glass

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within metamorphic/igneous matrix

Fossil bone or tooth fragment

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

Pyrite

Iron Sulfide (FeS2)

Likely weathered metallic mineral or slag fragment

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

Gold Ore in Quartz

Auriferous Quartz (Au + SiO2)

Pink faceted gemstone, likely amethyst or pink quartz

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

Granite

Felsic intrusive igneous rock

Quartz Vein in Host Rock (Gabbro or Basalt)

Silicon Dioxide (SiO2) with Mafic Silicates

Native Copper

Native Copper (Cu)

Indeterminate metallic mineral fragments

Possibly pyrite, chalcopyrite, or metallic sulfide-bearing rock

Pink Granite

Granite (Phaneritic Quartz-Feldspar rock)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Silver (Native Silver/Alloy Specimen)

Ag (Native Silver element), specifically a 90% Ag / 10% Cu alloy

Limonite and Goethite on Gossan

FeO(OH)·nH2O

Limonite and Goethite encrusted Quartz (Iron-stained Gossan)

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

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

Opalite

Synthetic Opalite Glass / Opalized Glass

Pyrite

Iron Disulfide (FeS2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Polished smoky quartz or brown chalcedony pebble

Silicon dioxide (SiO₂), likely quartz/chalcedony with iron-oxide inclusions

Gossan (Iron Hat) with Quartz and Chlorite

Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite

Pyrite (on a metal substrate)

Iron Sulfide (FeS2)

Quartz Vein in Host Rock

Crystalline Silicon Dioxide (SiO2) in Igneous/Metamorphic Matrix