Mineral (Man Made Glass)

Green Aventurine

Aventurine Quartz (SiO2 with Fuchsite inclusions)

Quartz (Iron-stained)

Silicon Dioxide (SiO2) with Iron Oxide impurities

Sandstone (Stream Pebble)

Arenite (primarily SiO2)

Quartzite

Quartzite (primarily SiO2)

Clear Quartz Point

Silicon Dioxide (SiO2)

Clear Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Chalcedony/Agate)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Aventurine

Silicon Dioxide (SiO2) with inclusions

Orange Calcite

Calcium Carbonate (CaCO3)

Celestite

Celestine (Strontium Sulfate, SrSO4)

Celestine (or Celestite)

Strontium sulfate (SrSO4)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Red Jasper

Jasper (Silicate Mineral - SiO2)

Green Aventurine

Quartzite (variety Aventurine) with Fuchsite inclusions (K(Al,Cr)2(AlSi3O10)(OH)2)

White Quartz Pebble

Silicon Dioxide (SiO2)

Ferruginous Sandstone (with possible Epidote/Chlorite coloring)

Sandstone (SiO2 dominated with Fe2O3 staining)

Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidote and Quartz)

Quartz Pebble (Sea Glass-like texture)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Quartz Vein on Matrix

Silicon Dioxide (SiO2)

Quartz Pebble

Crystalline Silicon Dioxide (SiO2)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Geode

Crystalline Quartz (Silicon Dioxide, SiO2)

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Agate Geode

Chalcedony (cryptocrystalline SiO2)

Green Quartz (Aventurine)

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

Obsidian

Volcanic Glass (predominantly SiO2)

Mahogany Obsidian

Volcanic Glass (SiO2 + Fe2O3)

Quartz with Chlorite or Hornblende inclusions

Silicon dioxide (SiO2) with phyllosilicate or amphibole inclusions

Milky Quartz (among River Rock)

Quartz (Silicon Dioxide, SiO2)

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)