Igneous Or Sedimentary (Anthropogenic Modification)

Pyrite

Iron Disulfide (FeS2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Gneiss

Gneiss (High-Grade Metamorphic Rock)

Quartz (Raw / Unpolished)

Silicon Dioxide (SiO2)

Bloodstone (Heliotrope)

Silicon Dioxide (SiO2) with Iron Oxide / Chlorite inclusions

Granite Gneiss

Granitoid Gneiss

Hematite

Iron Oxide (Fe2O3)

Hematite

Iron Oxide (Fe2O3)

Hematite

Iron Oxide (Fe2O3)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Imperial Topaz

Al2SiO4(F,OH)2

Pyrite in Matrix

Iron Sulfide (FeS2)

Epidote

Epidote (Ca2(Al2,Fe3+)3(SiO4)3(OH))

Quartz Crystal Cluster

Silicon Dioxide (SiO2)

Magnetite (Lodestone variant potential)

Magnetite (Fe3O4)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Orange Calcite

Calcium Carbonate (CaCO3)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Pyrite

Iron Disulfide (FeS2)

Mixed River Pebbles

Clastic Sedimentary Alluvial Deposit / Polymictic Conglomerate Clasts

Carnelian

Carnelian (Cryptocrystalline Quartz, SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Rainbow Hematite Ring

Iron(III) oxide (Fe2O3) with thin-film coating

White Quartz

Silicon Dioxide (SiO2)

Brown Agate

Silicon Dioxide (SiO2)

Calcite

Calcite (Calcium Carbonate - CaCO3)

Quartz

Silicon dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Carnelian

SiO2 (Microcrystalline Quartz / Chalcedony)

Pyrite

Iron Sulfide (FeS2)

Gneiss (Granitic Gneiss)

Gneiss

Pyrite in Matrix (likely Quartz or Schist matrix)

Iron Sulfide (FeS2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartz

Silicon Dioxide (SiO2)