Metamorphic Rock (Variety Of Quartz)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Geode (Quartz)

Silicon Dioxide (SiO2)

Vesicular Basalt (River Pebble)

Vesicular Basalt

Quartz (specifically Milky/Gray Quartz)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)

Carnelian (a variety of Chalcedony)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Quartzite (River Siltstone variety)

Quartzite (SiO2)

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Quartzite with Iron Staining

Silicon Dioxide (SiO2) with Fe2O3 impurities

Iron-stained Quartzite

Recrystallized Quartz (SiO2) with Hematite/Limonite staining

Quartzite

Quartzite (primarily SiO2)

River Cobble (Phyllite or Quartzite)

Metasedimentary Rock (often containing SiO2 or KAl2(AlSi3O10)(OH)2)

Red Quartzite River Pebble

Quartzite (SiO2 with iron oxide inclusions)

Granitic Gneiss

Gneiss (high-grade metamorphic rock primarily of quartz, feldspar, and mica)

Banded Agate (Onyx Variety)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Petrified Wood

Silicified Wood (SiO2)

Granite

Phaneritic Felsic Igneous Rock

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide staining/cementing)

Yellow Apatite Sphere (Polished)

Fluorapatite / Ca5(PO4)3F

Banded Chert (River Siltstone)

Microcrystalline Quartz (SiO2)

Red Quartzite (Tumbled Pebble)

Quartzite (primarily SiO2 with hematite inclusions)

Quartzite Pebble (River Rock)

Quartzite (primarily SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Dumortierite Quartz

Dumortierite-bearing Quartz (Al7BO3(SiO4)3O3)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Diorite (River Cobble)

Phaneritic Intermediate Igneous Rock

Diamond Drill Core (Greenschist and Quartzite)

Chlorite Schist / Meta-quartzite (Metamorphic Rock Core Sample)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Quartzite (Beach Pebble)

Quartzite (primarily SiO2)

Quartz in Host Rock

Silicon Dioxide (SiO2) in Rhyolite or Granite matrix

Gneiss (with Quartzite and Mica)

Gneiss

Gneiss (specifically Granite Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Conglomerate

Conglomerate (clastic sedimentary rock)

Quartzite

Quartzite (primarily SiO2)

Chert (and its variety Flint)

Silicon dioxide (SiO2) / Microcrystalline quartz

Chert (often called Flint in dark varieties)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Orthoclase Feldspar (Potassium Feldspar)

KAlSi3O8 (Potassium Aluminum Silicate)