Sedimentary (Imitation)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Chert (Flint variety)

Microcrystalline Quartz (SiO2)

Geode (unopened nodule)

Silicon Dioxide (SiO2) Nodule

Yellow Calcite

Calcium Carbonate (CaCO3)

Chert (Common Opal/Chalcedony mixture)

Silicon Dioxide (SiO2)

Calcite

Calcium Carbonate (CaCO3)

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Jasper

Silicon Dioxide (SiO2) with impurities

Clear Quartz

Silicon Dioxide (SiO2)

Clear Quartz Crystal

Silicon Dioxide (SiO2)

Chert (Flint variety)

Silicon Dioxide (SiO2)

Graphite

Graphite (Native Carbon), Formula: C

Metamorphic

Breciated Chert

Brecciated Chert (Microcrystalline Quartz, SiO2)

Green Aventurine

Silicon dioxide (SiO2) with fuchsite inclusions

Garnet (Almandine)

Almandine, Fe3Al2(SiO4)3

Blue Calcite

Calcium Carbonate (CaCO3)

Quartz (Milky/Crystalline variety)

Silicon Dioxide (SiO2)

Green Calcite

Calcium Carbonate (CaCO3)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Opal

Hydrated amorphous form of silica (SiO2·nH2O)

Garnet Schist or Garnet-bearing Quartzite

Metamorphic rock containing Almandine Garnet (Fe3Al2(SiO4)3) and Quartz (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Graphite

Graphite (Carbon, C)

Slate

Foliated Metamorphic Rock

Amethyst (Geode/Druzy)

Silicon Dioxide (SiO2) with iron impurities

Celestine (or Celestite)

Strontium sulfate (SrSO4)

Clear Quartz

Silicon Dioxide (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Gneiss

Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)

Almandine Garnet

Almandine (Fe3Al2Si3O12)

Pyrite (Iron Pyrites)

Iron Sulfide (FeS2)

Jasper (Chert)

Silicon Dioxide (SiO2)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Common Opal

Hydrated amorphous form of silica (SiO2·nH2O)

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Chalcedony (Quartz Var.)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)