Not A Rock (Man Made Polymer)

Opalite

Synthetic Opalite Glass

Pyrite in Quartz (Drill Core)

Silicon Dioxide (SiO2) with Iron Sulfide (FeS2) inclusions

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Asphalt (Bituminous pavement)

Bituminous concrete / Asphalt

Synthetic Resin (Artificial Specimen)

Polyurethane or Polyester Resin

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)

Concrete

Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Polished black pebble, likely basalt

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

Possible obsidian or slag glass

Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag

Quartzite (Engineered Stone)

Silicon Dioxide (SiO2) based synthetic composite

Opalite

Synthetic Opalite Glass / Opalized Glass

Rock crystal quartz fragments

Quartz (silicon dioxide, SiO₂)

Concrete with Exposed Aggregate

Anthropogenic conglomerate (Concrete)

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Polished dendritic agate or jasper

Microcrystalline quartz (SiO₂), likely chalcedony with iron/manganese dendrites

Iron Slag (Industrial Byproduct)

Anthropogenic Vitrification Product/Ferrous Slag

Mystic Topaz (Treated Quartz or Topaz)

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

Sandstone Concretion

Limonitic Sandstone Concretion

Note: This is a Man-Made Object (Costume/Prop Patch)

Synthetic fiber and pigments (Cellulose/Plastic-based composite)

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Vesicular basalt (probable iron-rich volcanic rock)

Basalt; chiefly plagioclase, clinopyroxene, olivine, and Fe-Ti oxides

Asphalt (Bituminous Concrete)

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

Crushed Stone (Likely Limestone or Granite)

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

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Slag

Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Green Sea Glass

Man-made silicate glass (weathered)

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial Man-made)

Opalite

Synthetic Opalite (Man-made glass)

Sandstone Concretion

Clastic Sedimentary Rock (primarily SiO2 with mineral cement)

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

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

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Slag Glass

Vitreous Silicate Residue

Slag (Industrial Glass/Glassy Rock)

Anthropogenic Vitreous Material

Chert Concretion (with typical hematite/limonite staining)

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

Opalite (Man-made Glass)

Fused glass (typically made of dolomite and metal opacifiers)

Quartz (Engineered Quartz Surface)

Silicon Dioxide (SiO2) based composite