Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
mineral (biogenic silica/calcium carbonate substrate)
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
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Honey-colored amber (likely copal or amber fragment)
Amber: fossilized plant resin; commonly succinite (C₁₀H₁₆O)
fossil
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Seashell Fossil
Gastropoda fossil
fossil
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)
sedimentary
Coprolite
Fossilized Feces
sedimentary
Fossilized Shell Fragment
Invertebrate marine fossil, likely calcium carbonate replacement
fossil
Dyed Coral
Calcium carbonate (CaCO3) - Calcite or Aragonite with dye
organic gemstone
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
mineral/sedimentary
Likely fossil shell fragment
Indeterminate mollusk fossil; possibly a gastropod or bivalve in limestone
fossil
Flint with Fossil Inclusion
Cryptocrystalline quartz (SiO2) enclosing fossilized organic remains
sedimentary
Turquoise-and-coral silver jewelry brooch
Turquoise: hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O; red cabochons appear to be coral, likely set in silver
gemstone
Shark Tooth Fossil
Carcharhiniformes or Lamniformes (order level fossil)
fossil
Megalodon Shark Tooth (Partial Fossil)
Otodus megalodon (fossilized in Calcium Phosphate/Apatite)
Mineral/Fossil
Fossilized Bivalve Shell (Fossilized Clam)
Bivalvia (class) / CaCO3 (Calcium Carbonate)
fossil
Fossil Coral
Cnidaria Anthozoa (Fossilized)
sedimentary
Fossilized Chiton (Polyplacophora)
Polyplacophora (fossilized valves)
mineralized fossil
Tumbled amber
Amber (fossilized tree resin; commonly succinite, C10H16O)
fossil
Fossilized Coprolite
Coprolite (fossilized feces)
sedimentary
Shark Tooth Fossil
Vertebrate fossilized tooth
fossil
Polished fossil-bearing amber cabochon (likely insect inclusion)
Fossilized plant resin; commonly Dominican or Baltic amber, chemically a complex diterpenoid resin
fossil
Polished amber-like chalcedony/jasper
Microcrystalline quartz (SiO₂), likely iron-stained chalcedony or jasper; amber cannot be confirmed visually
mineral
Fossiliferous Limestone
Limestone (Calcium Carbonate - CaCO3)
sedimentary
Dinosaur Fossil Tooth
Vertebrate Fossilized Tooth
fossil
Fossil shark tooth, likely megalodon
Otodus megalodon (formerly Carcharocles megalodon), fossilized tooth
fossil
Petrified Bone Pebble
Silicified Fossilized Bone
fossil
Fossilized Bivalve Shell
Class Bivalvia (fossilized)
fossil
Fossilized ammonite fragment
Ammonoidea; likely an ammonite suture-section specimen, commonly Jurassic–Cretaceous
fossil
Coprolite
Coprolite (fossilized feces)
sedimentary
Fossil gastropod in granite-like stone
Gastropoda indet.; enclosing rock likely polished granite or gneiss
fossil
Fossil Coral
Phylum Cnidaria / Rugosa or Tabulata
fossil
Fossil Coral
Scleractinia or Anthozoa (Fossilized)
fossil
Fossil Shark Tooth
Selachii (fossilized dentition)
fossil
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
sedimentary
Fossilized Bone
Permineralized Vertebrate Bone
fossil
Shark Tooth Fossil
Elasmobranchii dentition (fossilized)
fossil
Tiger Shark Fossil Tooth
Galeocerdo cuvier (fossilized)
sedimentary
Fossil bivalve shell
Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized
fossil
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Fossilized Bone
Petrified Bone (Fluorapatite / Calcium Phosphate replacement)
fossil
Sand Tiger Shark Tooth
Carcharias taurus (fossilized)
fossil