Organic (Geological Relative)

Pumice

Vesicular Rhyolite or Dacite

Petrified Wood

Silicified Wood (SiO2)

Blue Quartz

Quartz (SiO2) with inclusions

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)

Glauconite (Greensand)

Glauconite (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2

Chert (and Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Coral Fossil (Scleractinia)

Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)

Chert (specifically Jasper/Flint)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline 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 Fluorite

Calcium Fluoride (CaF2)

Green Chert

Microcrystalline Quartz (SiO2)

Banded Calcite (often sold as Onyx)

Calcite (Calcium Carbonate, CaCO3)

Petrified Wood

Silicified Wood (primarily SiO2)

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

Siliconized Wood (SiO2)

Fossil Coral (Rugosa or Solitary Coral)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Jasper)

Microcrystalline Quartz (SiO2) with Iron Oxide inclusions