Sedimentary And Igneous

Grey Chalcedony (Agate)

Silicon Dioxide (SiO2)

Pyrulite (Pyrite / Chalcopyrite)

Iron Sulfide (FeS2) or Copper Iron Sulfide (CuFeS2)

Pyrite

Iron Sulfide (FeS2)

Quartz

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz (Gray/Smoky Varieties)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz / Common Gravel

Silicon Dioxide (SiO2)

Quartz (Microcrystalline/Gravel)

Silicon Dioxide (SiO2)

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

Magnetite

Magnetite (Iron(II,III) oxide, Fe3O4)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Quartz

Silicon Dioxide (SiO2)

Epidote-bearing Rock / Epidote Inclusion

Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) in host rock

Quartz pebble

Quartz (Silicon dioxide, SiO2)

Hematite

Hematite (Fe2O3)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Blue Quartz

Silicon Dioxide (SiO2) with microscopic inclusions

Quartz

Silicon Dioxide (SiO2)

Quartz (Cut and Polished Sphere)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

River Gravel

Polymictic gravel and pebble aggregate

Quartz

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz (Clear Quartz / Rock Crystal)

Silicon Dioxide (SiO2)

Feldspar (Potassium Feldspar / Orthoclase)

KAlSi3O8 (Potassium Aluminum Silicate)

Polished Hematite Tower

Hematite (Fe2O3)

Quartz Pebble

Silicon Dioxide (SiO2)

Gneiss

Metamorphic Gneiss

Agate (or Operculum / Fossil Shell)

Silicon Dioxide (SiO2)

Quartz (Quartzite / Iron-stained Quartz)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (Smoky/Milky)

Silicon Dioxide (SiO2)

Golden Calcite

Calcium Carbonate (CaCO3)

Blue Calcite

Calcium Carbonate (CaCO3)

Quartz with inclusions

SiO2

Green Mica Schist

Mica Schist (Fuchsite or Chlorite variety)

Gneiss

Gneiss (Metamorphic high-grade)