Sedimentary Or Igneous

Carnelian Agate

Chalcedony (SiO2 with Iron Oxides)

Quartz (Crystal)

Silicon Dioxide (SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Milky Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss (Metamorphic Rock)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Pyrite

Iron Disulfide (FeS2)

Quartz Crystal

Silicon Dioxide (SiO2)

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Banded Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneiss

Pyrite (Fool's Gold) in Matrix

Iron Disulfide (FeS2)

Pyrite-bearing Rock

Iron Sulfide (FeS2)

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Hematite (likely Botryoidal or Specularite variant)

Iron(III) oxide (Fe2O3)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Tumbled Clear Quartz/Rock Crystal

Silicon Dioxide (SiO2)

Greenschist

Chlorite schist

Pyrite

Iron Disulfide (FeS2)

Green Schist

Greenschist (Chlorite Schist)

Carnelian

Carnelian (variety of Chalcedony, SiO2)

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hematite

Hematite (Iron(III) oxide, Fe2O3)

Chalcedony (Agate/Carnelian variety)

Cryptocrystalline Quartz (SiO2)

Feldspar (specifically Orthoclase or Plagioclase)

Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate

Pyrite

Iron Sulfide (FeS2)

Quartz (Grain)

Silicon Dioxide (SiO2)