Sedimentary (Man Made Composite)

Sandstone (with Liesegang rings or joints)

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide cement)

Stainless Steel (Polished)

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

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Unidentified translucent crystal/mineral fragment

Likely quartz (SiO₂), but visual identification is uncertain

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Asphalt (Bituminous pavement)

Bituminous concrete / Asphalt

Decorative gemstone-chip jewelry (likely turquoise, coral, and assorted beads)

Predominantly turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; other pieces appear to be dyed coral or red stone, and possibly shell/metal components

Sandstone Concretion

Septarian or Carbonate-cemented Sandstone Concretion

Brick fragment (Man-made material)

N/A (Fired clay)

Titanium Coated Kyanite (Aura Kyanite)

Aluminosilicate (Al2SiO5) with a Titanium-Niobium vacuum-deposited coating

Opalite

Synthetic Opalite Glass / Opalized Glass

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities

Slag (Industrial Byproduct)

Artificial silicate/iron byproduct

Turquoise cabochon ring

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

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Crescent Pebble

Weathered Quartzite or Sandstone Fragment

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Porcelain Tile (Sandstone-look)

Man-made Ceramic (resembling Quartz-rich Sandstone)

Boxwork or Septarian Concretion

Septarian nodule / Boxwork weathering

Transit Token (RTD Denver)

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

Mystic Topaz (Treated Quartz or Topaz)

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

Clear quartz fragment (rock crystal)

Quartz, silicon dioxide (SiO₂)

Concrete Rubble with Aggregate

Hardened Portland Cement Paste with Coarse Aggregate

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial Man-made)

Opalite

Synthetic Opalite (Man-made glass)

Opalite

Man-made Glass (SiO2 + additives)

Blue Slag Glass

Man-made Silicon Dioxide (Amorphous)

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Titanium-coated Metal Cube (Man-made Fidget Toy)

Titanium-anodized or electroplated alloy (e.g., Ti-coated Zinc or Aluminum)

Concrete with Exposed Aggregate

Anthropogenic conglomerate (Concrete)

Opalite

Man-made opalescent glass (SiO2 + metal oxides)

Green-and-white terrazzo (likely serpentine/marble aggregate)

Composite decorative stone; probable serpentinite (Mg₃Si₂O₅(OH)₄) with white calcite marble fragments in cementitious matrix

Opalite

Synthetic Glass (Silica-based)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Opaline Glass (Opalite)

Synthetic Silicon Dioxide Glass

Titanium Aura Quartz

Titanium bonded Silicon Dioxide (SiO2 + Ti)

Polished brown jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)