Tektite (Natural Glass)

Fulgurite

Fulgurite (Lechatelierite-rich fused silica)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Yellow Quartz (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Amethyst Quartz Crystal

Silicon Dioxide (SiO2) with iron impurities

Amethyst

Quartz (Silicon Dioxide with iron impurities), SiO2

Smoky Quartz

Silicon Dioxide (SiO2) with aluminum impurities and natural radiation

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Tumbled chert or flint pebble

Microcrystalline quartz (SiO₂), commonly with chalcedony and minor iron oxides

Pumice

Pumice (Silicic volcanic glass with vesicular structure)

Lepidolite

K(Li,Al)3(Si,Al)4O10(F,OH)2

Quartzite

Metamorphic Quartz (SiO2)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Sandstone (Quartzite-rich)

Clastic Sedimentary Rock (primarily SiO2)

Green Quartz (Prasiolite variant or Aventurine)

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining)

Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)

Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Granite

Phaneritic plutonic rock (SiO2 primary)

Smoky Quartz (with Hematite inclusions)

Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Blue Topaz

Aluminum silicate fluoride hydroxide (Al2SiO4(F,OH)2)

Quartzite

Quartzite (SiO2)

Ruby / Red Corundum

Al2O3 (Aluminum Oxide with Chromium trace)

River Quartzite Siltstone

Quartz-rich Meta-siltstone (SiO2 dominated)

Sandstone

Arenite (lithic or quartz sandstone)

Sandstone

Arenite

Pink Granite

Phaneritic intrusive felsic igneous rock

Black Chert (Flint)

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide / Chalcedony (SiO2)

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2) with iron oxide inclusions

Decorative polished pebbles

Likely mixed quartz-rich lithologies, including quartzite, jasper, and/or basalt

Quartz crystal pendant

Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz

Ferruginous Quartz (Agatized/Iron-stained Quartzite)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Tumbled granite

Granite, chiefly quartz, feldspar, and mica

Smoky Quartz

Silicon Dioxide (SiO2)

Sandstone (with Iron concretions/staining)

Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)