Organic (Pseudo Geological)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Limestone-based)

Silicon dioxide (SiO2)

Chrysanthemum Stone

Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (variant Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (with Limestone matrix)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert Nodules in Limestone

Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert (containing Flint and Calcareous inclusions)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities

Petrified Wood

Silicified Wood (primarily SiO2)

Green Chert

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Siliconized Wood (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2) with Iron Oxide inclusions

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Pyrite

Iron Sulfide (FeS2)

Chert (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Chert (often called Flint in this variation)

Silicon dioxide (SiO2) - Microcrystalline quartz

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite in Shaly Matrix

Iron Sulfide (FeS2)

Chert with Crinoid Fossil Impression

Microcrystalline Quartz (SiO2) with Crinoidea fossil impression

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Pyrite

Iron Sulfide (FeS2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert / Flint

Silicon Dioxide (SiO2)

Yellow Jasper / Chert

Jasper (Silica/Quartz) - SiO2

Chert (White Chert/Flint)

Chert (SiO2)

Fossil Shell (Bivalve)

Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Chert (White-Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Common Chert)

Silicon Dioxide (SiO2)

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Fossil Coral (Rugosa or Solitary Coral)

Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)

Agatized Fossil (Druzy Agate)

Silicon Dioxide (SiO2) replacing organic matter

Chert (Brown Variety)

Microcrystalline quartz (SiO2)

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)