Mineraloid (Organic)

Fossilized Bone Fragment

Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)

Fossiliferous Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Chert (within Asphalt)

Chert (SiO2)

Chert (specifically Tan/Yellow Chert)

Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)

Jasper

Cryptocrystalline Quartz (SiO2)

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Common Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Jasper

Jasper (Cryptocrystalline variety of Quartz, SiO2)

Chert (specifically Blue or Grey Chert/Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Jasper/Agate variety)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Crinoid Stem Fragment

Crinoid (Phylum Echinodermata, Class Crinoidea)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varietal: Flint or River Pebble)

Silicon Dioxide (SiO₂)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (and/or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant)

Cryptocrystalline Quartz (SiO2)

Banded Chert

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Orthoceras Fossil Limestone

Orthoceras sp. (Calcium Carbonate, CaCO3)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (often called Flint or River Rock)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Quartz Variety)

Chert (Silicon Dioxide, SiO2)

Chert (White Chert)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified wood (principally SiO2)

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint Pebble)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Fossil Shark Tooth (Otodus obliquus)

Otodus obliquus; hydroxyapatite (mineralized form Ca5(PO4)3(OH))

Red Chert (Jasper)

Chert / Microcrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Dendritic Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions

Chert (Chert Nodule with Cortex)

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Orthoceras Fossil in Limestone

Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone