Synthetic (Man Made Glass)

Milky quartz

Quartz (silicon dioxide, SiO₂)

Man-made earbud charging case (Not a rock or mineral)

Acrylonitrile Butadiene Styrene (ABS) Plastic with electronic components

Tumbled milky quartz

Quartz, silicon dioxide (SiO₂)

Diamond

Native Carbon (C)

Green iridescent glass cabochon or synthetic gemstone

Likely synthetic glass; possibly coated synthetic quartz or lab-created green gemstone

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

Blue opalite glass cabochon (likely imitation opal)

Man-made opalescent glass; not a natural mineral

Tumbled white chalcedony (likely milky quartz)

Chalcedony, microcrystalline quartz (SiO₂)

Tumbled milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Milky quartz (likely rough quartz crystal)

Quartz, silicon dioxide (SiO₂)

Goldstone

Man-made glass containing cuprous oxide

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2AlSi3O10(OH)2)

Glass

Amorphous Silicon Dioxide (SiO2)

Faceted gemstone in a jewelry setting

Indeterminate from image; likely quartz, cubic zirconia, or another transparent faceted stone

Cobalt Glass Slug (Cullet)

Man-made Silicate Glass with Cobalt Oxide (CoO)

Not a rock, mineral, or geological specimen

Blue Goldstone

Aventurine Glass

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Diamond (or Diamond Simulant)

Carbon (C) or Cubic Zirconia (ZrO2)

Man-made Green Quartz (Lab-grown or Treated)

Silicon Dioxide (SiO2) with artificial coloration

Polished milky quartz (likely quartz worry stone or wand)

Quartz, silicon dioxide (SiO₂)

White quartz pebble

Quartz (SiO₂), likely milky quartz

Goldstone (Brown/Gold)

Aventurine Glass (Man-made glass with Copper inclusions)

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Green Aventurine

SiO2 (Silicon Dioxide with Fuchsite inclusions)

Green glass-like mineral specimen, likely fluorite

Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass

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

Aventurine Quartz

Silicon Dioxide (SiO2) with Fuchsite inclusions

Goldstone (Synthetic Aventurescence Glass)

Cuprous Aventurescent Glass (Silicon Dioxide with Copper inclusions)

Small rounded mineral pebble, possibly quartz

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

Polished black pebble, likely basalt

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

Tumbled quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Slag Glass

SiO2 (Silicon Dioxide) with impurities

Concrete Fragment

Artificial Conglomerate (Cement and Aggregate)

Diamond (or Simulant)

Carbon (C)

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Opalite (likely imitation opal glass)

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

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (Industrial byproduct)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC) / Moissanite (natural)