Organic (Often Found By Beachcombers)

Chert (often called Flint or Jasper when pigmented)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Flint)

Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)

Travertine (Tufa)

Calcium Carbonate (CaCO3)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Fossilized Pycnodonte Oyster

Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)

Moss Agate

Agate (Silicon Dioxide, SiO2) with dendritic inclusions

Fossilized Shark Tooth (Basal Bone)

Otodus sp. (Mineralized Hydroxyapatite)

Mother of Pearl and Onyx

Aragonite (Mother of Pearl) and Chalcedony (Onyx)

Glauconitic Sandstone

Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically a weathered Chert nodule or fragment)

Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper)

Silicon Dioxide (SiO2)

Pyrite

Iron Sulfide (FeS2)

Anthracite Coal

Anthracite

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Petrified Wood

Silicified wood (principally SiO2)

Chert (Agatized Chert)

Microcrystalline Quartz (SiO2)

Agatized Chert / Chalcedony

Silicon Dioxide (SiO2)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Agate nodule)

Cryptocrystalline Quartz (SiO2)

Herkimer Diamond

Quartz (Silica - SiO2)

Fossilized Horn Coral

Order Rugosa (Rugose Coral)

Chert (often called Flint or River Stone)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Chert / Jasper / Agate (Chalcedony Group)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety)

Chert (Silicon Dioxide, SiO2)

Chert (often called Flint)

Chert (Silicon Dioxide, SiO2)

Chert (variously known as Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Black Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Amber

Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)

Red Coral (with Hematite and Black Pearl accents)

Corallium rubrum (Calcium Carbonate, CaCO3)

Jasper (specifically a banded or dark variety)

Silicon Dioxide (SiO2) with impurities

Amber

Succinite (Formula: C10H16O)

Shale or Slaty Mudstone

Argillaceous sedimentary rock

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Chert (Jasper)

Microcrystalline Quartz (SiO2)