Organic (Non Rock)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (varietal: Jasper or Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Arrowhead variety)

Chert (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Fossilized Gastropod (Snail)

Class Gastropoda (internal mold or 'steinkern')

Chert (specifically Pink/Tan Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Iron-stained Quartzite)

Silicon Dioxide (SiO2)

Mookaite Jasper

Silicified Radiolarite (SiO2)

Yellow Quartzite River Cobble

Meta-quartzite (SiO2 with iron oxide staining)

Pink Opal / Peruvian Opal

Hydrated amorphous silicon dioxide (SiO2·nH2O)

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically Banded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Yellow/Brown variety)

Chert (SiO2)

Man-made Ceramic / Clay Figurine

Aluminosilicate Ceramic (Processed Clay)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Chert / Flint

Microcrystalline Quartz (SiO2)

Chert (Nodule/Pebble)

Chert (Silicon Dioxide, SiO2)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Zebra Rock / Zebra Marble

Banded Limestone-Marble Transition

Conglomerate

Conglomerate (Detrital sedimentary rock)

Fossiliferous Limestone (Coquina / Shell Limestone)

CaCO3 (Calcium Carbonate)

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

Liesegang Ring Siltstone

Siltstone with iron oxide Liesegang bands

Dendritic Agate

Chalcedony (SiO2) with manganese/iron oxide inclusions

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Jasper with Quartz Vein

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Septarian Nodule (Dragon Stone)

Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)

Dendritic Agate (Tree Agate)

Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions

Tree Agate (or Moss Agate)

Dendritic Agate (Silicon Dioxide - SiO2)

Dragon Stone

Ohko Stone (Argillaceous sedimentary rock)

Coral Fossil (Petrified Coral)

Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)

Petrified Wood

Silicified Wood (SiO2)

Gastropod Steinkern (Fossil Snail Internal Mold)

Class Gastropoda (Internal Mold)

Fossiliferous Limestone (Coquina / Shell Limestone)

Bioclastic Limestone (CaCO3)

Chert (Jasper-bearing)

Chert (Silicon Dioxide, SiO2)

Quartzite River Rock with Dendrites

Metamorphosed Quartz-rich Sandstone with Manganese Oxide (MnO2) inclusions

Moss Agate

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

Ferruginous Chert

Microcrystalline Quartz (SiO2) with Iron Oxides

Chert (often called Flint or Jasper)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)