Sedimentary (Biogenic)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Muscovite Schist

Mica Schist (primarily KAl2(AlSi3O10)(OH)2)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

Flint (Chert)

Cryptocrystalline Quartz (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Opal

Hydrated Silica (SiO2·nH2O)

Yellow Jasper

Chalcedony (SiO2) with iron oxide inclusions

Honey Calcite

Calcium Carbonate (CaCO3)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Gold Nugget

Native Gold (Au)

Fluorite

Calcium Fluoride (CaF2)

Quartz (Milky/Crystalline)

Quartz (Silicon Dioxide, SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Optical Calcite (Iceland Spar)

Calcium Carbonate (CaCO3)

Pyrite (Iron Pyrite)

Iron Disulfide (FeS2)

Yellow Aventurine (or Citrine-colored Quartz)

Silicon Dioxide (SiO2) with inclusions

Gneiss (Banded Gneiss)

Gneiss

Chalcedony (Smoky Quartz or Agate nodule fragment)

Silicon Dioxide (SiO2)

Blue Apatite

Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Gold

Native Gold (Au)

Selenite (Satin Spar)

Gypsum (CaSO4·2H2O)

Breciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Orbicular Jasper (Ocean Jasper variant)

Silicon Dioxide (SiO2) with iron oxide inclusions

Chalcedony (Blue/Grey Lace Agate)

Silicon Dioxide (SiO2)

Agate (Carnelian-like)

Chalcedony (Silicon Dioxide, SiO2)

Chalcedony (Agate/Carnelian)

Cryptocrystalline Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Druzy Quartz on Chert/Siltstone

Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Magnetite / Iron Ore

Magnetite (Fe3O4)

Kyanite

Kyanite (Al2SiO5)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Banded Calcite (Mexican Onyx)

Calcite (CaCO3)

Yellow Calcite

Calcite (Calcium Carbonate, CaCO3)

Green Jasper

Jasper (Silicon Dioxide, SiO2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Mica Schist

Schist (Muscovite/Biotite Schist)

Quartz Mica Schist

Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)

Clear Quartz Fragment

Quartz (Silicon Dioxide, SiO2)