Man Made Composite

Blue Obsidian

Volcanic Glass (Amorphous)

Diamond (or Simulant)

Carbon (C)

Asphalt (Bituminous Concrete)

Composite material (bitumen binder with mineral aggregate)

Asphalt (Bituminous Concrete)

Bituminous Concrete / Pavement

Blue Goldstone

Man-made glass infused with copper crystals

Blue opalescent glass-like gemstone (possibly imitation opalite)

Likely man-made opalite glass; composition varies, typically silica-based glass

Sea Glass

Silicon dioxide (mostly)

Blue crystal pendant (likely blue glass or synthetic crystal)

Not identifiable from the image; possibly synthetic quartz or glass, rather than a natural mineral

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Mother of Pearl (Nacre) / Shell Fragment

Biogenic Calcium Carbonate (Aragonite and Conchiolin)

Small black stone fragment (possibly obsidian)

Unidentified dark rock; obsidian is volcanic glass (composition typically rhyolitic)

Obsidian

Volcanic Glass

Stainless Steel (Polished)

Ferrous Alloy containing Iron (Fe), Chromium (Cr), and Carbon (C)

Blue-green chrysocolla rough specimen

Chrysocolla, hydrated copper aluminosilicate; commonly associated with malachite, quartz, and limonite

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

Onyx (Black) and Mother of Pearl Inlay

Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl

Goldstone

Man-made glass with copper inclusions

Exposed Aggregate Concrete (Pea Gravel)

Concrete with Siliceous Alluvial Gravels

Decorated turquoise-like bead or mineral pendant

Likely turquoise [CuAl₆(PO₄)₄(OH)₈·4H₂O], possibly dyed composite or blue-green jasper

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

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Opalite

Synthetic Opalite (Man-made glass)

Opalite

Man-made Glass (SiO2 + additives)

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 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

Crushed Stone (Likely Limestone or Granite)

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

Turquoise cabochon ring

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Mystic Topaz (Treated Quartz or Topaz)

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

Sandstone Concretion

Limonitic Sandstone Concretion

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