Organic Gemstone (Sedimentary Associations)

Asphalt / Bituminous Aggregate

Bituminous mixture (Hydrocarbon-based sediment)

Chert (variations include Flint/Jasper)

Cryptocrystalline Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert with Quartz/Calcite Vein

Microcrystalline Silica (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (containing Fossil Inclusions)

Microcrystalline Quartz (SiO2)

Chert Pebble

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (CaCO3)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Chert (Black Chert/Flint)

Cryptocrystalline Quartz (SiO2)

Fossilized Crinoid Stem Segment

Crinoid (Phylum Echinodermata, Class Crinoidea)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (specifically Pink/Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (specifically Gray/Blue Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amber

Succinite (with empirical formula approximately C10H16O)

Chert (Limestone-hosted Pebble)

Sedimentary Cryptocrystalline Quartz (SiO2)

Ammonite Fossil

Ammonoidea (Calcium carbonate - CaCO3)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)

Petrified Wood

Silicified Wood (SiO2)

Septarian Nodule (Polished)

Septarian concretion (Calcite, Aragonite, Limestone)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (with inclusions)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Field Stone)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)

Chert (Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (and Limestone) River Cobble

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Chalky variety)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or River Stone)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Chert (and/or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossilized Coral

Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)

Jasper (Petrified Wood Variety)

Silicon Dioxide (SiO2)

Chert (Black Chert/Flint)

Silicon Dioxide (SiO2)

Glauconitic Sandstone (Greensand pebble)

Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)

Chert (and associated river cobbles)

Silicon dioxide (SiO2)