Industrial Byproduct (Anthropogenic Material)

Granodiorite

Granodiorite

Polished black stone, likely basalt or fine-grained mafic rock

Basalt (probable; identification uncertain from photograph)

Iron-rich laterite or limonite/goethite concretion

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and limonite (FeO(OH)·nH₂O)

Rounded yellow stone, possibly iron-stained chert or quartzite

Undetermined from image; likely microcrystalline quartz (SiO₂) if chert

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

Faceted garnet bead necklace

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

Natural turquoise-bearing rock

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a limonite or host-rock matrix

Weathered quartz-rich rock, possibly quartzite or chert

Quartz (SiO₂), likely in a quartzite matrix; exact identification is uncertain from the image

River Siltstone / Mudstone Pebble

Siltstone (composed of mixed silicate and carbonate minerals)

Weathered volcanic rock fragment

Indeterminate fine-grained mafic-to-intermediate igneous rock; possibly andesite or basalt

Dark metallic-looking mineral specimen, possibly magnetite

Magnetite (Fe₃O₄), tentative identification

Bauxite

Aluminum ore (mixture of gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH))

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

Asphalt Concrete

Bituminous conglomerate

Amber cabochon ring (likely amber)

Amber — fossilized plant resin; organic mineraloid, not a crystalline mineral

Faceted purple gemstone, likely amethyst

Quartz (SiO₂), purple variety colored by trace iron and natural irradiation

Sea Shell Fragment (Calcium Carbonate)

Aragonite / Calcite (CaCO3)

Likely metallic meteorite fragment

Undetermined iron or stony-iron meteorite; mineralogy requires testing

Quartzite

Quartzite (SiO2)

Polished/tumbled unakite (probable)

Unakite; epidote + pink potassium feldspar + quartz

Diamond

Carbon (C)

Diamond (or Cubic Zirconia / Gemstone Ring)

C (Carbon) for natural Diamond

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (primarily SiO2)

Dacite

Dacite (intermediate volcanic rock high in silica)

Ruby (faceted gemstone in a ring)

Corundum, Al₂O₃; red color typically from trace chromium

Banded agate tower (likely onyx/chalcedony)

Microcrystalline quartz, SiO₂; commonly called banded agate or black-and-white onyx

Likely dark smoky quartz

Quartz, silicon dioxide (SiO₂); identification is tentative from the photo

Asphalt (Bituminous pavement fragment)

Artificial conglomerate / Bitumen-Aggregate mixture

Concrete Paver (Artificial Cementitious Rock)

Hydrated Portland Cement Aggregate

Citrine (natural quartz crystal)

Quartz, SiO₂; the yellow-brown color may be natural citrine or heat-treated amethyst

Diamond (or Diamond Simulant/Cubic Zirconia)

Carbon (C) - if diamond, or Zirconium dioxide (ZrO2) - if Cubic Zirconia

Mica Schist

Metamorphic Schist

Dyed druzy agate/geode (likely dyed quartz)

Quartz, SiO₂, lining a chalcedony geode; vivid pink color appears artificially dyed

Blue sodalite-bearing rock

Likely sodalite (Na₈(Al₆Si₆O₂₄)Cl₂) in a white feldspathic matrix; exact identification is uncertain from the image.

Possible pink quartz specimen in a dark matrix

Uncertain from the image; possibly rose quartz (SiO₂) attached to a dark host rock

Rough blue-gray sapphire (possible corundum)

Corundum, Al₂O₃; sapphire is gem-quality corundum

Small quartz-rich rock fragment

Unidentified quartz-bearing rock; the image is insufficient for a precise identification

Bivalve shell fossil or modern shell

Calcareous bivalve shell, composed mainly of calcium carbonate (typically aragonite and/or calcite); species cannot be determined from this view

Small pink-red mineral fragment, possibly ruby or corundum

Corundum (Al₂O₃), unconfirmed; visual identification is uncertain

Black tourmaline (schorl)

Schorl, NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

Likely polished labradorite (small tumbled stone)

Labradorite, a plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Likely quartz-rich pebble

Quartz-bearing granite, granitic gneiss, or quartzite (indeterminate from photo)