Sedimentary Rock (Technically A Microcrystalline Quartz Mineral Aggregate)

Quartz in Host Rock

Silicon Dioxide (SiO2) in Rhyolite or Granite matrix

Carnelian

Carnelian (SiO2 - Silicon Dioxide)

Banded Agate (specifically Lake Superior Agate style)

Silicon Dioxide (SiO2) - Chalcedony variety

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Chert (containing Calcite or Quartz inclusions)

Silicon Dioxide (SiO2) with varying mineral impurities

Quartzite

Quartzite (SiO2)

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Quartzite pebble

Quartzite (SiO2)

Banded Gneiss

Gneiss (Metamorphic high-grade rock)

Quartzite Pebble

Metamorphic Quartz (SiO2)

Granite

Granite (Felsic Plutonic Rock)

Granite (weathered/river-tumbled)

Granite (Plutonic Igneous Rock)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

White Chalcedony (Agate)

Silicon Dioxide (SiO2)

Red Quartzite (River Pebble)

Quartzite (primarily Silicon Dioxide - SiO2)

Dalmatian Stone

Dalmatian Stone (a peralkaline igneous rock consisting of Feldspar, Quartz, and Arfvedsonite)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (with Iron Oxide)

Arenite with Limonite/Hematite staining

River Rock (Greywacke/Siltstone)

Siltstone / Argillaceous Greywacke

Pink Quartzite

Quartzite (primarily SiO2)

Ocean Jasper

Orbicular Jasper/Microcrystalline Quartz (SiO2)

Jasper

Chalcedony (cryptocrystalline quartz), SiO2

Sandstone

Arenite (primarily SiO2, silica)

Clear Quartz

Silicon Dioxide (SiO2)

Quartzite Pebbles

Meta-quartzite (SiO2)

Sandstone (Ferruginous)

Arenite (Fe-bearing Clastic Sedimentary Rock)

Quartz River Cobble

Silicon Dioxide (SiO2)

Ferruginous Quartz (Iron-Stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Carnelian Agate

Carnelian (SiO2 with iron oxide impurities)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Blue Chalcedony

Silicon Dioxide (SiO2)

Gneiss

Foliated Metamorphic Rock (Gneiss)

Red Quartz (Carnelian/Red Jasper Agate)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Red Sandstone

Arenite (with Iron Oxide)

Granite

Phaneritic plutonic rock (approx. 20-60% quartz, 35-90% feldspar)

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

Granite

Phaneritic Acidic Igneous Rock (Granite Group)

Granite (Granitic Pegmatite/Porphyry)

Felsic intrusive igneous rock (Quartz, Feldspar, Mica composition)

Granite

Granite (Felsic Plutonic Rock)

Red Jasper

Silicon Dioxide with Iron inclusions (SiO2)

Limonitic Sandstone (Stained Sandstone)

Clastic Sedimentary Rock with Iron Oxide (Limonite/Goethite) staining