Man Made Material (Anthropogenic 'Mineraloid')

Aura Quartz (Rainbow Quartz)

Silicon Dioxide (SiO2) with metallic vapor coatings

Small pebble, likely limestone

Unidentified carbonate pebble, possibly micritic limestone (calcite, CaCO₃)

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

Blue glassy gemstone cabochon, likely dyed chalcedony or glass

Uncertain; possible dyed chalcedony (microcrystalline quartz, SiO₂)

Asphalt Chunk (Bituminous Concrete)

Aggregated Bitumen / Artificial Breccia

Opalite

Synthetic Glass (Hydrated Silica Simulant)

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Iron-rich slag or ironstone; appearance is not diagnostic

Likely iron-oxide-rich material (hematite, Fe₂O₃, and/or magnetite, Fe₃O₄); possibly smelting slag

Hematite

Iron(III) oxide (Fe2O3)

Black Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Mother of Pearl (Nacre)

Aragonite (CaCO3) with Organic Matrix

Ferrous Slag

Iron/Steel Slag (Complex Calcium-Alumino-Silicates)

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Slag Glass (Cullet)

Amorphous Silica (man-made), primarily SiO2 with trace metal oxides

Diamond (or Simulant)

Carbon (C)

Blue-green cabochon, likely chalcedony or treated glass imitation

Cryptocrystalline quartz (chalcedony/possibly chrysoprase); identification uncertain from image

Goldstone (Brown/Gold)

Aventurine Glass (Man-made glass with Copper inclusions)

Fossiliferous limestone with colonial coral

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

Ferruginous Slag (Iron Smelting Byproduct)

Anthropogenic Vitreous Silicate (often containing Fayalite: Fe2SiO4)

Bouncy Ball (Synthetic Rubber Polymer)

Polybutadiene / Ethylene Vinyl Acetate (EVA)

Cultured Marble (Synthetic)

Polymer-matrix composite (typically calcium carbonate in polyester resin)

Sea Glass

Silicon dioxide (mostly)

Slag

Ferrous slag (by-product of iron smelting)

Quartz pebble (Quartztite fragment)

Silicon Dioxide (SiO2)

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Asphalt Chunk

Asphalt concrete

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Opalite

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

Blue opalite glass (likely man-made)

Opalite glass; a silica-based amorphous glass, not natural opal

Polished labradorite sphere

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

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Opalite

Man-made Opalized Glass (Synthetic Glass)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Opalite (likely man-made opalescent glass)

Opalite; not a true mineral, typically synthetic opalescent glass (silica-based)

Obsidian

Volcanic Glass (SiO2)

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Polished brown jasper (likely brecciated or orbicular jasper)

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

Cherry Quartz with Rose Quartz

Crystalline Quartz (SiO2) with glass-based synthetic components

Man-made Synthetic Material (Plastic/Composite)

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