Man Made Rock Like Material

Fossiliferous limestone with colonial coral

Calcite (CaCO₃) limestone containing fossil tabulate or rugose coral colonies

Asphalt (Bituminous Concrete)

Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)

Mother of Pearl (Nacre)

Aragonite (CaCO3) with Organic Matrix

Man-made Synthetic Material (Plastic/Composite)

Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)

Polished black pebble, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Sandstone Concretion

Septarian or Carbonate-cemented Sandstone Concretion

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Green sea glass (likely)

Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock

Sea Glass

Man-made silicate glass

Clear Quartz Sphere (Rock Crystal)

Silicon Dioxide (SiO2)

Goldstone (with Tiger's Eye and Quartz)

Aventurine glass (Synthetic SiO2 with Cu inclusions)

Blue-green faceted gemstone, possibly glass or synthetic material

Not identifiable from the image; possible synthetic spinel or glass

Polished labradorite sphere

Labradorite, calcic plagioclase feldspar ((Ca,Na)(Al,Si)₄O₈)

Sea Glass

Man-made vitreous material (silica-based glass)

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Opalite (a synthetic glass)

Silicon Dioxide (SiO2) with various additives; not a true mineral but a man-made gem simulant

Sandstone Concretion

Limonitic Sandstone Concretion

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Opalite

Synthetic Opalized Glass

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Opalite

Man-made Synthetic Glass (Silicon Dioxide with metal additives)

Green sea glass (likely bottle glass)

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

Note on Image Identification: Textile

N/A (Anthropogenic material)

Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Stainless Steel (Polished)

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

Blue Slag Glass

Anthropogenic Amorphous Silicon Dioxide

Ferro-silicate Slag

Industrial Vitrified Slag (High-silica amorphous glass)

Asphalt Chunk (Bituminous Concrete)

Aggregated Bitumen / Artificial Breccia

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Tumbled black stone, likely black obsidian

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

Polished obsidian

Volcanic glass; predominantly rhyolitic SiO₂

Slag Glass

SiO2 (Silicon Dioxide) with impurities

Transit Token (RTD Denver)

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

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Carborundum (Silicon Carbide)

Silicon carbide (SiC)

Opalite

Opalescent Glass (SiO2 + coloring agents)

Conglomerate

Conglomerate Rock (Paraconglomerate)

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)

Opalite

Synthetic Opalite Glass / Opalized Glass