Antropogenic (Man Made Glass Byproduct)

Small pebble, likely limestone

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

Obsidian

Volcanic Glass

Aura Quartz (Titanium/Rainbow Quartz)

SiO2 (Silicon Dioxide) with metallic coating

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Concrete

Anthropogenic Conglomerate

Opalite

Synthetic opalescent glass

Aventurine Quartz

Silicon Dioxide (SiO2) with Fuchsite inclusions

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

Small rounded mineral pebble, possibly quartz

Uncertain; likely microcrystalline or crystalline SiO₂ (quartz), potentially with iron-oxide staining

Opalite (Synthetic Moonstone/Sea Opal)

Silicon Dioxide (SiO2) glass with metallic inclusions

Polished black pebble, likely basalt

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

Opalite

Synthetic Glass (Hydrated Silica Simulant)

Tumbled quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Opalite (Man-made Glass)

Synthetic Opalised Glass

Blue cabochon, likely dyed or synthetic material

Undetermined; possibly dyed chalcedony (SiO₂), glass, or synthetic corundum

Opalite

Man-made opalescent glass (SiO2 + metal oxides)

Diamond (or Simulant)

Carbon (C)

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Tumbled opalite (likely man-made glass)

Opalite glass; a synthetic opalescent glass, not a natural mineral species

Opalite (likely imitation opal glass)

Man-made opalescent glass; not a natural mineral (often sold as opalite)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC) / Moissanite (natural)

Opalite

Synthetic Opalized Glass (SiO2 + additives)

Blue opalite glass (likely man-made)

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

Opalite

Synthetic Opalite Glass

Opalite crescent pendant

Opalite (man-made opalescent glass; not a natural mineral)

Opalite

Synthetic Opalised Glass

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Slag Glass (Cullet)

Amorphous Silica / Glass residue

Polished black stone, likely black obsidian

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Iron-rich slag or ironstone; appearance is not diagnostic

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

Sea Glass

Man-made vitreous material (silica-based glass)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

White quartz pebble or chip

Quartz (silicon dioxide, SiO₂), possibly milky quartz

Unidentified translucent crystal/mineral fragment

Likely quartz (SiO₂), but visual identification is uncertain

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Opalite

Synthetic Fluorescent Glass (SiO2 + impurities)

Pink Quartz / Sea Glass

Silicon Dioxide (SiO2)

Goldstone (Red)

Aventurine Glass (Cupriferous glass)

Iron Slag

Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)

Sea Glass

Man-made silicate glass (Amorphous silicon dioxide)

Opalite (Man-made Glass)

Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)