Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Category
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Crinoid Stem Fossil
Crinoid columnal (Echinodermata)
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Order: Rugosa)
Petoskey Stone
Hexagonaria percarinata
Fossil Coral (Petoskey-style Rugose Coral)
Hexagonaria percarinata (Order: Rugosa)
Jet
Lignite (Anthracite-grade compact coal)
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (variations like Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Bivalve Fossil (Clam)
Class Bivalvia (e.g., Mercenaria or similar genus)
Kimberlite
Kimberlite
Pink Orthoclase Feldspar with Dendrites
Orthoclase (KAlSi3O8) with Manganese Oxide dendrites
Dendritic Opal
Opalized Chalcedony with Manganese Inclusions (SiO2 · nH2O)
Picture Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Petoskey Stone (Fossilized Rugose Coral)
Hexagonaria percarinata
Fossiliferous Shale or Slate with Plant Fossils
Fossil-bearing argillaceous rock
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Chert (Nodule)
Chert (composition: SiO2)
Chert (with Lichen)
Microcrystalline Quartz (SiO2)
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Yellow Chert (Chert / Cryptocrystalline Quartz)
Silicon Dioxide (SiO2)
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Chert / Chalcedony
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Fossilized shell fragment
Indeterminate fossil mollusk; likely a silicified or mineral-replaced bivalve/gastropod fragment
Fossilized oyster shell
Bivalvia; likely an oyster (Ostreidae), partly mineralized with calcite
Fossilized Oyster Shell
Gryphaea or Exogyra (Family Ostreidae)
Fossilized Horse Tooth
Equus sp. (Tooth)
Fossilized Horn Coral
Rugosa (Order)
Fossilized Bone Chunk
Permineralized Vertebrate Bone (indeterminant)
Fossilized Gastropod Shell
Gastropoda (Class) replacement / internal cast (steinkern)
Fossilized Brachiopod Shell
Order Spiriferida (likely)
Fossilized Shark Tooth
Elasmobranchii (various species, possibly Carcharias or Odontaspis)
Fossilized Shell Fragment
Bivalvia or Gastropoda (Class) fragment
Fossilized Horse Tooth
Equus ferus caballus (fossilized molar/premolar)
Fossilized Mosasaur Tooth
Mosasauridae (likely Prognathodon or Mosasaurus)
Fossilized Bivalve in Limestone
Class Bivalvia within Sedimentary Matrix (likely CaCO3)