Mineral (Silicate Replaced Organic Material)

Moss Agate

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

Shale

Shale (clay-sized silicate minerals)

Chert (specifically Flint)

Silicon Dioxide (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Otodus Shark Tooth

Otodus obliquus

Weathered iron-rich rock, possibly basalt or ironstone

Indeterminate; likely Fe-oxide-bearing basaltic rock (commonly magnetite/hematite in a silicate matrix)

Fossilized tooth, likely a mammalian tooth fragment

Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth

Petrified Wood

Silicified wood / Xylopal

Petrified Wood

Silicified Wood (primarily SiO2)

Yellow-brown jasper or silicified volcanic rock

Microcrystalline quartz (chalcedony), SiO₂, likely jasper

Chert (and Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (specifically a Chert Nodule or Flint)

Cryptocrystalline Quartz (SiO2)

Amber

Succinite (fossilized resin, C10H16O)

Chrysocolla in Chalcedony (Gem Silica)

Hydrated copper phyllosilicate and silicon dioxide (SiO2 with (Cu,Al)2H2Si2O5(OH)4)

Chert

Microcrystalline Quartz (SiO2)

Yellow Chert

Microcrystalline Quartz (SiO2)

Fossil Shark Tooth (Sand Tiger or Mackerel Shark)

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

Fossilized Shark Tooth (fragment)

Elasmobranchii (Class) fossil

Green Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Chert (Flint Nodules)

Chert (Microcrystalline Quartz, SiO2)

Chert (varietal: Jasper or Ironstone nodule)

Microcrystalline Quartz (SiO2) with iron oxides

Lapis Lazuli

Lapis Lazuli (Rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)

Chert (River Cobble)

Chert (Cryptocrystalline Quartz, SiO2)

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Chert (Gravel pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossilized Wood / Petrified Wood

Petrified Wood (Silicified Flora)

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Red Jasper

Microcrystalline Quartz (Chalcedony), SiO2

Polished fossiliferous limestone pebble

Fossiliferous micritic limestone, probably containing gastropod or bivalve fragments

Tiger's Eye (often misinterpreted as Gold Ore in this context)

Pseudomorph of Quartz after Crocidolite (SiO2)

Fossilized Sand Tiger Shark Tooth

Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)

Fossiliferous Rock (likely Dinosaur Fossil in Matrix)

Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)

Chert (often called Jasper or Flint)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert (Cherty Shale / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Banded Chert / Agate

Silicon Dioxide (SiO2)

Jasper

Jasper (Silicon Dioxide) - SiO2