Man Made Object (Metalwork)

Black glassy fragment, likely obsidian or industrial glass

Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Green sea glass (likely bottle glass)

Man-made soda-lime silicate glass; not a natural mineral

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Granite (with a dark inclusion or attached fragment)

Granite, mainly quartz, feldspar, and mica; the dark object cannot be identified confidently from the photo.

Polished black stone, likely obsidian

Obsidian (volcanic glass; mostly silica-rich rhyolitic composition)

Goldstone

Man-made glass with copper inclusions

Exposed Aggregate Concrete (Pea Gravel)

Concrete with Siliceous Alluvial Gravels

Orgonite Pyramid (containing Amethyst and mixed minerals)

Silicon Dioxide (SiO2) in synthetic resin

Concrete Fragment

Hardened Portland cement and mineral aggregate

Opalite

Synthetic Opalite Glass / Opalized Glass

Asphalt Concrete

Bituminous conglomerate

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities

Slag (Industrial Byproduct)

Artificial silicate/iron byproduct

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Blue chalcedony (likely dyed or treated)

Microcrystalline quartz, SiO₂ (chalcedony)

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Opalite

Synthetic Opalite (Man-made glass)

Opalite

Man-made Glass (SiO2 + additives)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Transit Token (RTD Denver)

Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)

Goldstone

Man-made glass with copper inclusions

Blue Slag Glass

Man-made Silicon Dioxide (Amorphous)

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Green Sea Glass

Man-made silicate glass (weathered)

Likely slag-encrusted ironstone or a small mineralized rock fragment

Unidentifiable from the image; possibly iron-oxide-rich material (hematite/goethite) with adhering dark slag or debris

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

Likely iron-rich slag or weathered ironstone fragment

Uncertain; possibly iron oxide–rich material (hematite/goethite) or industrial iron slag

Blue-green faceted gemstone, possibly glass or synthetic material

Not identifiable from the image; possible synthetic spinel or glass

Asphalt (Road Aggregate)

Bituminous conglomerate

Crushed Stone (Likely Limestone or Granite)

Calcium Carbonate (CaCO3) for Limestone / Quartz and Feldspar for Granite

Mystic Topaz (Treated Quartz or Topaz)

Aluminum silicate fluoride hydroxide [Al2SiO4(F,OH)2] with thin-film metallic coating

Sandstone Concretion

Limonitic Sandstone Concretion

Polished obsidian

Volcanic glass; predominantly rhyolitic SiO₂

Likely citrine or yellow glass imitation in a silver-tone bracelet

Citrine: quartz, SiO₂; exact material cannot be confirmed visually

Tumbled milky chalcedony (likely common opalite-like quartz)

Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O

Gold ring with a clear faceted gemstone

Likely diamond (carbon, C); the photograph is insufficient to confirm the stone or metal

Terrazzo (Man-made Composite)

Cementitious or Resin-bound Lithic Composite

Faceted clear gemstone in a gold-colored setting

Unidentified transparent faceted stone; possibly quartz, glass, or another colorless gem

Concrete Paver (Artificial Cementitious Rock)

Hydrated Portland Cement Aggregate

Unidentifiable Rock Fragment