Tektite (Natural Glass)

Green Aventurine

SiO2 (Quartz) with inclusions of Fuchsite

Green Aventurine

SiO2 (Silicon Dioxide with inclusions of Fuchsite)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Blue Aventurine

Silicon Dioxide (SiO2) containing Dumortierite or Crocidolite inclusions

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

River Quartzite (River Stone)

Quartzite (primarily SiO2)

Green Aventurine

Silicon Dioxide (Quartz variety) with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Green Aventurine

SiO2 (Silicon Dioxide) with Fuchsite inclusions

Green Aventurine

Silicon dioxide (SiO2) with Fuchsite inclusions

Green Aventurine (Double-Terminated Wand)

Silicon Dioxide (SiO2) containing Fuchsite (Chromium-rich Muscovite Mica)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Green Aventurine

Aventurine Quartz (SiO2 + Muscovite/Fuchsite)

Green Aventurine

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

Aventurine

Silicon Dioxide (SiO2) with inclusions

Obsidian

Obsidian (principally SiO2 + MgO, Fe3O4)

Tumbled pink quartz (likely rose quartz)

Quartz, silicon dioxide (SiO₂), likely rose quartz

Sandstone

Arenite

Sandstone

Arenite

Pearl (Cultured or Natural)

Aragonite (CaCO3) with Conchiolin

Blue glass-like beaded bracelet (material uncertain)

Possibly dyed blue agate or another blue stone; the image does not allow reliable mineral identification

Turquoise cabochon jewelry

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Weathered granite fragment

Granite, chiefly quartz (SiO₂), feldspar, and mica

Sandstone

Arenite (SiO2 with minor iron oxides)

Amethyst bead bracelet

Quartz, SiO₂; purple variety colored mainly by iron-related defects and irradiation

Faceted blue gemstone ring, likely synthetic spinel or glass; identity uncertain

Possibly synthetic blue spinel (MgAl₂O₄) or laboratory sapphire (Al₂O₃); the clear side stones may be cubic zirconia or glass

Obsidian

Volcanic Glass (SiO2)

Red gemstone ring, likely garnet or synthetic ruby

Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish

Amethyst geode

Quartz, SiO₂; purple variety amethyst, commonly a drusy-lined geode

Tumbled chert or flint

Microcrystalline quartz (SiO₂), commonly termed chert; dark varieties are called flint

Green Quartzite (with Hematite inclusions)

Metamorphic Quartz (SiO2) with various inclusions

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxide-coated

Quartz Pebble

Silicon Dioxide (SiO2)

Citrine

Silicon dioxide (SiO2)

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Black Obsidian

Obsidian (Volcanic Glass, SiO2+)

Blue Sapphire

Corundum (Al2O3) with traces of Iron and Titanium

Purple chalcedony or lavender quartz

Cryptocrystalline quartz, SiO₂ (likely chalcedony; identification uncertain from photograph)

Tumbled yellow quartz, likely citrine or iron-stained quartz

Quartz (SiO₂), possibly citrine variety

Slag (Industrial Glass)

Artificial Vitreous Silicate

Likely black cabochon gemstone pendant

Uncertain; possibly black star sapphire, black spinel, or obsidian

White quartz pebble

Quartz (silicon dioxide, SiO₂)