Igneous, Sedimentary, Metamorphic, Mineral

Gneiss

Gneiss

Schist

Metamorphic Rock (Schist)

Pyrite

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Blue Calcite

Calcium Carbonate (CaCO3)

Green Calcite

Calcium Carbonate (CaCO3)

Pyrite

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Specular Hematite

Iron(III) oxide (Fe2O3)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Orange Calcite

Calcium Carbonate (CaCO3)

Blue Calcite

Calcium Carbonate (CaCO3)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Milky Quartz

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Quartz (Gravel Pebble)

Silicon Dioxide (SiO2)

Yellow Quartz (Citrine / Milky Quartz)

Silicon Dioxide (SiO2)

Quartz (Smoky Quartz / Chalcedony)

Silicon Dioxide (SiO2)

Gneiss with Quartz Veining

Gneiss (High-grade Metamorphic Rock)

Gneiss

Foliated Metamorphic Rock

Quartz (Clear or Milky)

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Quartz Sand Gravel

Silicon Dioxide (SiO2)

Titanium Quartz (Aura Quartz)

Silicon Dioxide (SiO2) treated with Titanium

Labradorite (a variety of Feldspar)

Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)

Banded Gneiss

Gneiss (Felsic to Mafic Metamorphic Rock)

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Quartz (Grain)

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade metamorphic rock)

Quartz (Clear Quartz)

Silicon Dioxide (SiO2)

Quartz (Small Fragment)

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Gneiss

Metamorphic Gneiss

Quartz pebble

Silicon dioxide (SiO2)

Blue Calcite

Calcium Carbonate (CaCO3)

Banded gneiss (likely amphibolite-bearing gneiss)

Gneiss; quartz–feldspar–mica/amphibole aggregate

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)