Fossilized Coral (Petoskey Stone / Chain Coral)
Scleractinia (Order) / Halysites (Genus for Chain Coral types)
sedimentary
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Fossilized Resin) in the encyclopedia
View all →
Brachiopod Fossil
Phylum Brachiopoda (replaced by Calcite or Silica)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary
Tumbled yellow quartz (likely citrine or iron-stained quartz)
Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration
mineral
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Synthetic/Man-made Polymer
Ammonite Fossil
Ammonoidea
fossil
Fossilized Rugose Coral (Petoskey Stone precursor)
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Polished orbicular jasper / brecciated jasper
Jasper, microcrystalline quartz (SiO₂), with iron-oxide and clay-rich inclusions
sedimentary
Bumblebee Jasper (technically a type of Agate/Anhydrite)
Calcite and Anhydrite with inclusions of Realgar and Orpiment (As2S3)
sedimentary
Fossilized Shark Tooth (Sand Tiger)
Carcharias sp. (Fossilized Tooth)
fossil
Petrified Wood
Fossilized wood / Silicified wood
Sedimentary / Fossil
Fossil Coral
Scleractinia (fossilized calcium carbonate)
sedimentary
Stromatolite
Cyanobacteria fossilized formation (CaCO3)
sedimentary
Red Coral
Corallium rubrum
gemstone
Terrazzo (with Marble and Granite fragments)
Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates
sedimentary (man-made composite)
Chert (Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Petoskey Stone
Hexagonaria percarinata
fossil
Petoskey Stone (Weathered/Rough Form)
Hexagonaria percarinata
fossil
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Fossilized Coral (Petoskey Stone or similar)
Hexagonaria percarinata (Order: Rugosa)
sedimentary
Obsidian and Fossilized Shark Tooth
Obsidian (Volcanic Glass) and Otodus sp. (Fossilized shark tooth)
igneous and fossil
Jasper
Microcrystalline Quartz (SiO2)
gemstone
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite
mineral
Petoskey Stone
Hexagonaria percarinata
fossil
Favosites (Honeycomb Coral Fossil)
Favosites sp. (Phylum Cnidaria, Order Tabulata)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossil Coral / Crinoid Stem section
Anthozoa / Crinoidea fossil
fossil
Fossil Sea Urchin / Echinoid
Class Echinoidea
fossil
Fossil Sea Urchin (Echinoid)
Echinoidea fossil (often replaced by silica or calcite)
fossil
Sandstone (Quartzose)
Sandstone (SiO2 dominated)
sedimentary
Petoskey Stone
Hexagonaria percarinata
fossil
Sandstone
Arenite (SiO2 based)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Fossiliferous Limestone (Coral Fossil)
Calcium Carbonate (CaCO3) with Colonial Coral inclusions
sedimentary
Kambaba Jasper (Crocodile Jasper)
Stromatolite (Fossilized Algae within Microcrystalline Quartz), SiO2
sedimentary
Sandstone (with potential Concretion or Fossil fragment)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary