Igneous, Sedimentary, Metamorphic

Green Schist

Greenschist (composed primarily of Chlorite, Actinolite, and Epidote)

River Stone (Granitic Gneiss)

Foliated Granitic Gneiss

Gneiss

Metamorphic rock of high-grade regional metamorphism

Gneiss

Gneiss (High-grade metamorphic rock)

Sandstone (Micaceous Sandstone)

Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)

Quartz (in a rock matrix)

Quartz (SiO2)

Arkosic Sandstone (or Conglomeritic Sandstone fragment)

Arkose (rich in feldspar)

Coarse Sand Grain / Lithic Fragment

Clastic Sediment (Lithic fragment or Quartz/Feldspar grain)

Quartz

Quartz (SiO₂)

Magnetite or Hematite (Iron Stone)

Magnetite (Fe3O4) or Hematite (Fe2O3)

Pyrite

Iron Sulfide (FeS2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Common variant)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

White Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Magnetite (Lodestone variety)

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

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Magnetite / Ironstone

Magnetite (Fe3O4)

Pyrite on Quartz

Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pyrite (Fools Gold)

Iron Sulfide (FeS2)

Gneiss

Banded Metamorphic Rock (Gneiss)

Gneiss (River Cobble)

Gneiss (Foliated Metamorphic Rock)

Gneiss

Gneiss (Metamorphic high-grade)

Quartz

Silicon Dioxide (SiO2)

Schist

Mica Schist (Metamorphic rock)

Tourmaline (likely Schorl)

Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Mixed River Stones and Minerals

Mixed Silica-rich Stones (Quartz, Agate, Jasper, Sandstone, Dalmation Stone)

Biotite or Phlogopite Mica

K(Mg,Fe)3(AlSi3O10)(F,OH)2

Gneiss

High-grade Metamorphic Gneiss

Gneiss

Foliated Metamorphic Rock (Gneiss)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Gneiss with Quartz Veining

Gneiss (High-grade regional metamorphic rock)

Quartz Pebble

Silicon Dioxide (SiO2)

Gneiss

Gneiss

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)