Organic Gemstone (Fossilized Resin)

Chert (Smooth River Pebble)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (specifically River Stone / Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper depending on color)

Chert (SiO2 - Microcrystalline or Cryptocrystalline Quartz)

Chert (Nodule/Pebble)

Chert (Silicon Dioxide, SiO2)

Green Sandstone

Glauconitic Sandstone

Chert (variant Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Carnelian

Carnelian (subset of Chalcedony); SiO2 with Iron Oxide impurities

Amethyst (Faceted Gemstone)

Silicon Dioxide (SiO2) with iron impurities

Aquamarine

Beryl (Be3Al2Si6O18)

Tanzanite

Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))

Coquina Limestone (Fossiliferous Limestone)

Calcareous bioclastic sedimentary rock (CaCO3)

Chert Pebble (Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert Pebble (Flint)

Microcrystalline/Cryptocrystalline Quartz (SiO2)

Chert (Nodule)

Chert (SiO2)

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)

Chert (varieties: Flint or Chalcedony)

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified wood (SiO2 - Silicon Dioxide)

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Yellow Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Gravel specimen)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limonite-stained Chert

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Petrified Wood

Silicified wood (Quartz variant, SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood)

Silicified Paleoflora (mainly Quartz, SiO2)

Limestone (specifically Fossiliferous or Crinoidal Limestone)

Calcium Carbonate (CaCO3) - Calcite Rock

Chert (specifically Chalcedony or Flint variation)

Microcrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Coquina / Fossiliferous Limestone

Coquina (composed primarily of Calcium Carbonate / CaCO3)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pink Chert (Brecciated Jasmine/Jasper)

Silicon Dioxide (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified wood (Quartz, SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)