Sedimentary And Igneous

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Beach Pebble (Quartz / Quartzite)

Silicon Dioxide (SiO2)

Gneiss

Metamorphic Foliated Gneiss

Banded Agate (Dyed / Polished)

Microcrystalline Quartz (SiO2)

Green Fluorite

Calcium Fluoride (CaF2)

Magnetite

Magnetite (Fe3O4)

Banded Agate (specifically Eye Agate)

Chalcedony (Silicon Dioxide, SiO2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Carnelian Agate

Chalcedony (SiO2 with Iron Oxides)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Gneiss

Gneiss (Metamorphic Rock)

Gneiss

Gneiss

Chalcedony (Agate/Chert variety)

Silicon Dioxide (SiO2)

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Quartz (Milky/Smoky variety)

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold) in Matrix

Iron Disulfide (FeS2)

Gneiss

Gneiss

Clear Quartz (Rock Crystal)

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)

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Pyrite-bearing Rock

Iron Sulfide (FeS2)

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Banded Gneiss

Gneiss (Metamorphic Rock)

Pyrite

Iron Disulfide (FeS2)

Green Schist

Greenschist (Chlorite Schist)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz Crystal

Silicon Dioxide (SiO2)

Hematite (likely Botryoidal or Specularite variant)

Iron(III) oxide (Fe2O3)

Carnelian

Carnelian (variety of Chalcedony, SiO2)

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hematite

Hematite (Iron(III) oxide, Fe2O3)