Chert (Jasper/Chalcedony pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
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Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (often called Flint or Agate nodule)
Cryptocrystalline Quartz (SiO2)
sedimentary
Ammonite fossil
Ammonoidea; likely a polished small ammonite, possibly Cleoniceras
fossil
Fossil shark tooth
Likely Otodus megalodon (species identification uncertain from image)
fossil
Chert (Blue-Gray Chert)
Microcrystalline quartz (SiO2)
sedimentary
Chert (var. Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Rugose Coral Fossil
Rugosa (Order)
sedimentary
Fossil Rugose Coral (Horn Coral)
Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)
sedimentary
Horn Coral Fossil
Rugosa (Order Rugosa)
sedimentary
Mookaite Jasper
Silicon Dioxide (SiO2) with various inclusions
sedimentary
Sandstone
Arenite (mainly SiO2 with varying cements)
sedimentary
Jasper with Manganese Dendrites
Silicon Dioxide (SiO2) with Oxide Mineral Inclusions
sedimentary
Sandstone Cobble with Liesegang Rings
Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)
sedimentary
Liesegang Banded Sandstone (Wonderstone)
Ferruginous Sandstone with Liesegang Rings
sedimentary
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)
Mineraloid (Organic Gemstone)
Fossilized Coral (Rugose or Tabulate) or Stromatolite
Phylum Cnidaria / Stromatolithus
fossil
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossilized Coral (Petoskey Stone or similar Rugose Coral)
Hexagonaria percarinata (or similar Rugose/Tabulate coral)
fossil
Blue Opal Inlay (Simulated/Lab-created)
Hydrated Amorphous Silica (SiO2·nH2O) with polymer resin
mineraloid
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Fossilized shell or brachiopod
Likely a calcareous brachiopod or bivalve fossil; exact identification requires clearer detail and scale
fossil
Fossilized bivalve shell
Bivalvia (likely a venerid or similar clam); shell composed mainly of CaCO₃ as aragonite/calcite
fossil
Fossilized bivalve shell
Bivalvia indeterminate; likely a fossil cockle or clam shell, aragonite/calcite replaced or preserved
fossil
Fossilized Sand Dollar
Echinoidea (Clypeasteroida)
fossil
Fossilized Gastropod Steinkern
Class Gastropoda internal mold
fossil
Fossilized Horn Coral
Rugosa (Rugose coral)
fossil
Fossilized Gastropod Shell
Gastropoda (Fossilized internal mold or shell body)
fossil
Fossilized Shark Tooth
Elasmobranchii (tooth fossil, composed mainly of Bioapatite / Calcium Phosphate)
fossil
Fossilized Shark Tooth
Carcharocles sp. or similar Lamniformes
fossil
Fossilized Shark Tooth
Selachii (Elasmobranchii subclass)
fossil
Fossilized Oyster Shell
Exogyra or Ostrea (Gryphaeidae/Ostreidae family)
fossil
Fossilized Tabulate Coral
Favosites (Honeycomb Coral)
fossil
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Basalt (with possible dendritic inclusions)
Extrusive mafic igneous rock
igneous
Fossilized Blastoid (Sea Bud)
Pentremites sp. (Echinodermata, Blastoidea)
fossil
Fossilized Shark Tooth (Scapanorhynchus)
Scapanorhynchus texanus
fossil
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Green variety)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary