Mineral

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Granite

Granite, a coarse-grained felsic intrusive igneous rock composed mainly of quartz, feldspar, and mica

Polished granite or gneiss stone

Granite, chiefly quartz, feldspar, and dark mica/amphibole; exact identification is uncertain from the photograph

Fossilized Gastropod / Coral

Phylum Mollusca / Cnidaria (Silicified or Calcified)

Quartz with Associated Minerals

Silicon Dioxide (SiO2)

Limonite

FeO(OH)•nH2O

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂), likely milky or druzy quartz

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Pegmatite

Granitic pegmatite, composed mainly of quartz and feldspar with possible mica

Jade (likely Jadeite)

Jadeite (a pyroxene mineral) or Nephrite (a variety of amphibole mineral)

Quartz Vein in Sedimentary Rock

Silicon Dioxide (SiO2) with host Chert or Limestone

Tumbled Mixed Gemstones and Rocks

Various mineral species including quartz (SiO2) and silicate minerals

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Blue-green copper mineral (possibly chrysocolla or turquoise)

Undetermined from the image; chrysocolla is a hydrated copper silicate, Cu₂H₂O₅Si, while turquoise is CuAl₆(PO₄)₄(OH)₈·4H₂O

Rounded, mottled pebble (likely granitoid)

Probable granitic or dioritic rock; exact identification requires closer inspection

Quartz Crystal

Silicon Dioxide (SiO2)

Faceted red garnet

Garnet group, likely almandine (Fe₃Al₂(SiO₄)₃)

Faceted garnet bead necklace

Garnet group, likely almandine (Fe₃Al₂(SiO₄)₃); exact species cannot be confirmed from the image

Rounded, weathered stone (likely basaltic or andesitic river cobble)

Fine-grained mafic to intermediate volcanic rock; exact identification requires examination of a fresh surface

Petrified wood

Silicified fossil wood; commonly quartz (SiO₂) replacing woody tissue

Rounded gray pebble, likely andesite

Probably andesite; identification from the photo is uncertain

Amygdaloidal Basalt with Quartz Veining

Basalt (Extrusive Igneous Rock) with Quartz (SiO2) veining

Gneiss

Gneiss (foliated metamorphic rock)

Granite with Mafic Xenolith

Intrusive Igneous Rock (Felsic to Intermediate)

Granite

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)

Granite

Granite (Felsic Plutonic Rock)

Small brown mineral or rock fragment

Undetermined; the image does not show enough detail for reliable identification

Unidentified polished mineral specimen

Indeterminate; likely a pale feldspar or quartz-bearing material

Blue apatite specimen

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F)

Tumbled yellow-green stone, possibly serpentine

Serpentine-group minerals, commonly antigorite or lizardite; identification from the image is uncertain

Travertine

Calcium Carbonate (CaCO3)

Limonite (Yellow Ochre)

Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)

Limonite (Iron Ore)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Microcline Feldspar (Amazonite or White Feldspar)

KAlSi3O8

Pegmatite

Igneous Pegmatite

Quartz Mineral

Silicon Dioxide (SiO2)

Gold Mineral

Native Gold (Au)

Kaolinite (clay mineral)

Kaolinite, Al₂Si₂O₅(OH)₄

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Quartz Mineral

Silicon dioxide (SiO2)

Quartz Mineral

Silicon Dioxide (SiO2)

Quartz Mineral

Silicon Dioxide (SiO2)