Mineral (Silicate Replaced Organic Material)

Fossiliferous Flint

Microcrystalline Quartz (SiO2) with Echinoid Fossil

Fossilized Shark Tooth

Carcharodon carcharias (fossilized) / Hydroxyapatite permineralized with silica or iron

Tumbled chert or flint pebble

Microcrystalline quartz (SiO₂), likely chert; exact variety uncertain from the image

Slag (Industrial Glassy Byproduct)

Ferro-silicate Slag

Green Moss Agate

Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite

Weathered mineralized rock fragment

Indeterminate; likely quartz–feldspar-rich lithic material with iron-oxide staining

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Fossilized Shark Tooth (Root Portion)

Selachimorpha (partial specimen)

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

Fossilized Coral

Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Chalcedony (Agate/Seashell replacement)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Rhodonite

Manganese Silicate (MnSiO₃)

Glass

Amorphous Silicon Dioxide (SiO2)

Sandstone (Banded)

Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide staining)

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide)

Chert (Jasper variation)

Chert (Silicate mineral, SiO2)

Petrified Bone (Fossil Bone)

Per mineralization fossil bone (varies by organism, predominantly replacement by SiO2 - Quartz/Chalcedony)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Weathered gray stone, possibly basalt or granitic rock

Indeterminate fine- to medium-grained silicate rock; possible basalt, diabase, or weathered granite

Jasper (specifically Yellow Jasper and Red Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Glendonite (Calcite Pseudomorph after Ikaite)

Calcite (CaCO3) pseudomorph after Ikaite (CaCO3·6H2O)

Petrified Wood

Silicified Wood (SiO2)

Small rounded stone or mineral fragment

Indeterminate; likely a common quartz- or feldspar-bearing silicate fragment

Polished chrysocolla-bearing copper mineral specimen

Chrysocolla, Cu₂H₂Si₂O₅(OH)₄·nH₂O, likely mixed with malachite and limonite/goethite

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Fossilized Shark Tooth

Lamniformes (order) fossil

Petrified Bone Pebble

Silicified Fossilized Bone

Fossilized oyster shell

Ostrea/Exogyra sp.; calcium carbonate (mostly calcite)

Tumbled orange-and-white jasper or brecciated chalcedony

Microcrystalline quartz (SiO₂), likely iron-oxide-stained jasper; exact variety cannot be confirmed from the image

Petrified Wood

Silicified Wood (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Polished Ocean Jasper cabochon

Ocean jasper: microcrystalline quartz (SiO₂), commonly mixed with chalcedony, feldspar, and iron/manganese oxides

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of cellulose)

Amygdaloidal Basalt with Agate/Quartz Infill

Basalt with Secondary Silicate Mineralization (SiO2)

Poppy Jasper

Microcrystalline Quartz (SiO2) with mineral inclusions

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Petrified Wood (Calamites Fossil)

Calamites sp. (Silicified/Permineralized Plant Fossil)

Fossilized Horn Coral

Order Rugosa (Rugose Coral)