Mineral (Synthetic Glass)

Iron-stained Quartz

Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)

Rounded quartz-rich beach pebble

Likely milky quartz or quartzite (SiO₂)

White Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Iron-Stained)

Crystalline Silicon Dioxide (SiO2)

Obsidian

Obsidian (Volcanic Glass)

Clear quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Obsidian

Volcanic glass (SiO2-rich extrusive igneous rock)

Pegmatite (Feldspar and Quartz)

Pegmatite (KAlSi3O8 / SiO2)

Clear quartz crystal (likely vein quartz)

Quartz, silicon dioxide (SiO₂), most likely colorless macrocrystalline quartz

Snowflake Obsidian

Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)

Quartz vein in Schist

Crystalline Silicon Dioxide (SiO2) in Metamorphic Host

Possible rough green tourmaline (verdelite)

Tourmaline group; commonly elbaite, Na(Li₁.₅Al₁.₅)Al₆Si₆O₁₈(BO₃)₃(OH)₄

Glass

Amorphous Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz-rich rock, likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly a quartzite fragment

Obsidian

Volcanic glass

Snowflake Obsidian

Volcanic glass containing Spherulite inclusions (primarily Cristobalite, SiO2)

Milky quartz fragment (likely quartz-rich mineral)

Quartz, silicon dioxide (SiO₂)

Quartz Vein / Quartz Matrix

Silicon Dioxide (SiO2)

Polished black stone, likely obsidian

Volcanic glass; chiefly amorphous SiO₂

Quartz crystal beads

Quartz (silicon dioxide, SiO₂)

Muscovite Mica

KAl2(AlSi3O10)(OH)2

Sandstone with Mineral Veining or Crust

Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)

Blue Goldstone

Aventurine Glass (Silicon Dioxide with metal inclusions)

Green glassy mineral fragment, likely peridot or green fluorite

Possibly olivine (forsterite–fayalite series), Mg₂SiO₄, or fluorite, CaF₂; exact identification requires testing

Likely rough quartz-rich rock (identification uncertain)

Possibly milky quartz with iron-oxide staining; exact identification is not possible from the image alone.

Tumbled quartz crystal

Quartz (silicon dioxide, SiO₂)

Green sea glass (likely bottle glass)

Human-processed soda–lime silicate glass; not a natural mineral or rock

Tumbled gray stone, likely quartz-rich pebble

Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite

Likely translucent quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Polished black gemstone, likely obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately SiO₂)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Green glass sphere/marble

Soda-lime glass (primarily SiO2, Na2O, CaO)

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Quartz crystal fragment (likely milky/inclusion-rich quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled blue glassy mineral, possibly sodalite or blue aventurine

Identification uncertain; likely sodalite (Na₈Al₆Si₆O₂₄Cl₂) or blue-dyed quartz/slag-like material

Obsidian

Volcanic Glass

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Polished pink quartz pebble, likely rose quartz

Quartz, silicon dioxide (SiO₂), with trace iron, titanium, or manganese

Milky quartz cluster

Quartz, silicon dioxide (SiO₂)