Polished ammonite fossil pendant
Ammonite; likely a polished, mineral-replaced ammonoid shell (commonly Calcite or Aragonite)
fossil
Category
Mineralized Fossil
Browse mineralized fossil specimens identified by the Rock Identifier community.
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Jasper with Agate and Quartz Inclusions
Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate
sedimentary
Sandstone
Arenite
sedimentary
Fossilized Horn Coral
Rugosa (Rugose coral)
fossil
Fossil Coral (Tabulate Coral Fragment)
Anthopleura / Tabulata (CaCO3 - Calcium Carbonate)
fossil
Pyrite
Iron Sulfide (FeS2)
mineral
Fossilized Shark Tooth
Fossil Chondrichthyes (various genera such as Carcharias or Odontaspis)
sedimentary
Tumbled turquoise (probable)
Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O
mineral
Polished fossil coral pendant
Agatized or silicified colonial coral; commonly sold as fossil coral jasper
fossil
Sand Tiger Shark Tooth
Carcharias taurus
fossil
Agatized Fossil Coral
Agatized Anthozoa
fossil
Bivalve Internal Mold Fossil
Steinkern (Bivalvia mold)
fossil
Rugose Coral (Horn Coral) Fossil
Order Rugosa (likely Grewingkia or Zaphrentis genus)
fossil
Fossilized Brachiopod
Phylum Brachiopoda (Calcium Carbonate/Silica replacement)
sedimentary
Ironstone Concretion
Ironstone (primarily Siderite or Limonite / Goethite, FeO(OH)·nH2O)
sedimentary
Petrified Wood
Silicified wood (primarily quartz replacing organic cellulose)
fossil
Petrified Coral (Agatized Coral)
Fossilized Anthozoa (Silicon Dioxide replacement - SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
mineral
Sedimentary Rock Fragments
Clastic Sedimentary Rock
sedimentary
Sandstone
Sandstone (clastic sedimentary rock)
sedimentary
Weathered iron-rich pebble
Likely limonite/goethite-bearing rock; exact identification requires testing
mineral
Quartz-bearing iron-rich rock, possibly quartzite or hydrothermal breccia
Quartz (SiO₂) with iron oxides/hydroxides, likely limonite/goethite; exact host rock is uncertain from the photograph
metamorphic
Coprolite
Coprolite
sedimentary
Ammonite Fossil
Ammonoidea subclass (calcium carbonate / silica replacement)
fossil
Sand Tiger Shark Tooth
Carcharias taurus (fossilized)
fossil
Fossiliferous limestone
Calcite-rich limestone (CaCO₃), possibly coral or shell-bearing
sedimentary
Fossiliferous limestone pebble
Calcite-rich limestone containing possible brachiopod or coral fossil impressions
fossil
Silicified fossil-bearing chert
Microcrystalline quartz (SiO₂), likely chalcedony replacing carbonate shell material
fossil
Blue-green chrysocolla rough specimen
Chrysocolla, hydrated copper aluminosilicate; commonly associated with malachite, quartz, and limonite
mineral
Fossil Coral / Fossilized Coral
Scleractinia (Anthodiscus / Favia / Montastraea fossil)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz / Chalcedony replacement)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (mainly Quartz/Chalcedony, SiO2)
fossil
Fossilized Coral
Rugosa / Tabulata coral fossils replaced by silica (Chalcedony/Quartz)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Quartz-bearing metamorphic rock (likely quartz vein in schist or altered granite)
Quartz (SiO₂) in a mica-rich host rock; exact identification requires testing
metamorphic
Brachiopod Fossil
Phylum Brachiopoda
fossil
Seashell Fossil
Invertebrate fossil (phylum Mollusca)
fossil