Glass

Feldspar (Orthoclase)

Potassium Alveolar Silicate (KAlSi3O8)

Sandstone

Arenite (SiO2 based)

Sandstone (Quartzite-rich Pebble)

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite with Iron Oxides

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Quartz Geode (Water-worn)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 based)

Sandstone with Concretions / Liesegang Rings

Arenite with iron oxide banding

Sandstone

Arenite (SiO2 predominantly)

Sandstone (Quartz-rich)

Arenite

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Gray/Smoky Variety)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Iron Inclusions

Crystalline Silicon Dioxide (SiO2)

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz Pebble (with Iron Inclusions)

Silicon Dioxide (SiO2)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Milky Quartz

Silica (SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Gravel)

Silicon Dioxide (SiO2)

Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartz (Iron-stained or Milky)

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily Silicon Dioxide, SiO2)

Quartzite Pebble

Quartzite (SiO2)

Quartzite pebble

Quartzite (SiO2)

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)