Organic (Often Found By Beachcombers)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint Nodules)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite in Shale

Iron Disulfide (FeS2) in Sedimentary Shale

Fossilized Coral

Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)

Moss Agate

Silicon Dioxide (SiO2) with mineral inclusions of hornblende or chlorite

Quartzite and Chert

Silicon Dioxide (SiO2)

Chert (variations include Flint or Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified wood (Quartz, Chalcedony, or Opal)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Coquina

Biogenic Limestone (Calcium Carbonate - CaCO3)

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert with Quartz/Calcite Vein

Microcrystalline Silica (SiO2)

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Shale

Shale (Sedimentary rock composed of mud/clay minerals)

Chert (Flint)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Jasper/Mudstone)

Silicon Dioxide (SiO2)

Chert (Quartz)

Microcrystalline Silica (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (often called Flint or Jasper)

Silicon Dioxide (SiO2)

Chert (Green variety)

Chert (Silicon Dioxide, SiO2)

Asphalt / Bituminous Aggregate

Bituminous mixture (Hydrocarbon-based sediment)

Chert (Nodular)

Microcrystalline Silica (SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Ironstone Concretion (Ironstone Gourd)

Limonite/Goethite Concretion (FeOO(H))

Pink Opal

Hydrated silicon dioxide (SiO2·nH2O) with inclusions

Chert (Yellow Jasper/Flint)

Silicon Dioxide (SiO2)

Druzy Quartz on Vesicular Basalt

Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (Field Stone)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Fossil Shark Tooth (Otodus obliquus)

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

Chert (specifically Iron-stained or Jasperoid Chert)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (often called Flint)

Cryptocrystalline Quartz (SiO2)

Shale or Siltstone

Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)