Organic (Often Found By Beachcombers)

Chert (Flint)

Silicon Dioxide (SiO2)

Red Chert (Jasper)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Fossil Shark Tooth (Sand Tiger or Mackerel Shark)

Carcharias sp. or Otodus sp. replaced by Hydroxylapatite/Calcium Carbonate

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (and Flint variant)

Microcrystalline Quartz (SiO2)

Knightia Fossil in Limestone

Knightia eocaena in micritic limestone

Black Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Amber

Succinite (Organic Mineraloid)

Chert (Jasper/Flint variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Onyx (Black) and Mother of Pearl Inlay

Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl

Coquina (Fossiliferous Limestone)

Coquina (Organic Clastic Limestone)

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Chert (Arrowhead variety)

Chert (SiO2)

Chert (Smooth River Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with fossil inclusions

Amber

Succinite (fossilized resin)

Chert / Jasper

Microcrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline context of Quartz (SiO2)

Chert / Flint

Chert (Silicon Dioxide, SiO2)

Chert Pebble

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (Flint Nodules)

Silicon Dioxide (SiO2)

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Chert (concretionary/nodular variant)

Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions

Black Marble

Recrystallized Calcite (CaCO3)

Amber

Succinite (Resin C10H16O)

Chert (Nodule)

Silicon Dioxide (SiO2)

Jasper Agate

Silicon dioxide (SiO2)

Fossilized Bone Fragment

Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)

Chert (often called Jasper in this color)

Microcrystalline quartz (SiO2)

Chert (Chert Nodule in Limestone)

Microcrystalline Quartz (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Jasper with Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Pyrite Geode

Iron Disulfide (FeS2)

Flint

Chert (Silicon dioxide, SiO2)

Fossilized Crab Carapace (Concretion)

Decapoda (fossil), typically preserved in calcite or siderite concretion

Chert / Chalcedony

Silicon Dioxide (SiO2)

Yellow Jasper (Chert)

Silicon Dioxide (SiO2) with iron inclusions