Mineral (Man Made Glass)

Amethyst crystal fragment

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron and irradiation

Sandstone (Quartzose)

Arenite (primarily SiO2)

Goldstone

Aventurine Glass (SiO2 + Cu small inclusions)

Larimar

Pectolite

Sandstone (Quartzose)

Arenite (primarily SiO2)

Goldstone (blue-goldstone–style glass) beads

Artificial aventurine glass, typically silica glass with copper inclusions; not a natural mineral

Chalcedony (Agate / Jasper Specimen)

Silicon Dioxide (SiO2)

Smoky Quartz

Smoky Quartz (SiO2)

Precious Coral (Red Coral)

Corallium rubrum (Calcium Carbonate, CaCO3)

Diamond (in a jewelry setting)

Carbon (C)

Tektite

Natural impact glass

Diamond (or Cubic Zirconia simulant)

Carbon (C) - Diamond / Zirconium dioxide (ZrO2) - CZ

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone (Pebble)

Sandstone (SiO2 with matrix/cement)

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Rounded quartz pebble

Quartz (silicon dioxide, SiO₂)

Polished smoky quartz crystal point

Quartz (SiO₂), likely iron-colored or smoky quartz with milky inclusions

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Sandstone

Arenite (SiO2 based clastic rock)

Corundum (Sapphire variant)

Aluminium oxide (Al2O3)

Blue Slag Glass

Ferro-silicate glass (Slag)

Blue Goldstone

Aventurine Glass (Silicon Dioxide with metal inclusions)

Blue opalite (often sold as synthetic opal)

Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)

Rough Corundum (Sapphire/Ruby mixture)

Corundum (Aluminum Oxide, Al2O3)

Dark quartz point (possibly smoky quartz)

Quartz, SiO₂; the dark color may indicate smoky quartz, but the image is insufficient to confirm

Sandstone (Quartz Arenite)

Sandstone (dominated by SiO2 quartz grains)

Polished black stone pendant

Likely black obsidian or black tourmaline; exact identification is uncertain from the photograph

Sandstone

Arenite (SiO2 primarily)

Chert

Silicon dioxide (SiO2)

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Granite

Felsic intrusive igneous rock

Aura Quartz / Rainbow Aura Quartz

Silicon Dioxide (SiO2) with metallic vapor coating

Chert / Flint

Microcrystalline Quartz (SiO2)

Pink Granite

Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)

Jasper Marble

Silicon Dioxide (SiO2) with Impurities

Beaded gemstone jewelry (likely amethyst, lapis lazuli, and pearl or glass imitation)

Mixed mineral beads; possible quartz (SiO₂) and lazurite-bearing lapis lazuli

Sandstone

Clastic sedimentary rock (primarily SiO2)

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Goldstone (Red)

Aventurine Glass

Yellow chalcedony (likely lemon agate or yellow jasper)

Microcrystalline quartz, SiO₂; possibly iron-bearing jasper or chrysoprase-like chalcedony

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)