Organic (Non Geological)

Chert (Smooth River Pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Chert Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Chert (or Flint)

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Banded Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (specifically Iron-stained River Cobble)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Jasper variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (specifically Chert Nodule/Flint)

Chert (Silicon Dioxide, SiO2)

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Banded Agate (specifically Moss Agate or Plume Agate variety)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (variant Flint/Jasper)

Microcrystalline Opaline Silica (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (specifically Jasper or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Limestone with Chert or Siltstone bands

Sedimentary carbonate rock (CaCO3) often with siliceous impurities

Jasper (likely Brown or Brecciated)

Jasper (Silicon Dioxide, SiO2)

Blue Agate (Tumbled and Dyed)

Silicon Dioxide (SiO2) with likely organic dyes

Arid Sandy Loam

Arenosols / Regosols

Chert (Nodule)

Chert (SiO2)

Amber

Fossilized Tree Resin (C10H16O)

River Stone (likely Mudstone or Siltstone)

Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Petrified Wood

Silicified Wood (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline silicon dioxide (SiO2)

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Granite

Granite (a felsic intrusive igneous rock)

Chert (Brecciated Chert)

Silicon Dioxide (SiO2)

Chert (Brecciated or Veined)

Silicon Dioxide (SiO2)

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides

Banded Chert (Ironstone/Jasper)

Cryptocrystalline Quartz (SiO2) with Iron Oxides

Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende, chlorite, or manganese/iron oxides

Moss Agate

Chalcedony (Silicon Dioxide with inclusions) - SiO2

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)