Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)
Category
Mineral (Biogenic Replacement)
Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
fossil
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
sedimentary
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Pebble)
Silicon Dioxide (SiO2)
sedimentary
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
fossil
Chert (Nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Stromatolite
Biogenic sedimentary structure (Stromatolite)
fossil
Stromatolite
Laminated biogenic sedimentary structure (Cyanobacteria)
sedimentary
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Chert (Flint)
Microcrystalline or cryptocrystalline quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Spiny Oyster Shell
Spondylus (Calcium Carbonate, CaCO3)
mineral
Limestone with Chert
Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions
sedimentary
Likely fossilized shell or carbonate concretion
Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)
fossil
Chert (Flint / Chalcedony pebble)
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (and associated Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (and Fossiliferous Limestone)
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
mineral
Coral limestone / fossil coral
Biogenic calcium carbonate, chiefly aragonite or calcite (CaCO₃); likely fossilized colonial coral
fossil
Fossiliferous Chert
Cryptocrystalline quartz (SiO2) with biogenic inclusions
sedimentary
Chert or flint with chalcedony/quartz veins
Microcrystalline silica: primarily quartz (SiO₂), including chalcedony; possible fossiliferous limestone or silicified material
sedimentary
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
sedimentary
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Chert
Chert (microcrystalline quartz, SiO2)
sedimentary
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
mineral
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
mineral
Cleavable Calcite
Calcium Carbonate (CaCO3)
mineral
Brachiopod Fossil
Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)
sedimentary
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
mineral
Sea Snail Shell (Top Shell)
Trochidae family (Calcium Carbonate, CaCO3)
mineral
Seashell Fragment (Aragonite/Calcite)
Calcium Carbonate (CaCO3) - Shell fragment
sedimentary
Mixed Gemstone Collection
SiO2 (Quartz varieties) and Biogenic CaCO3 (Nacre)
mineral
Abalone Shell (Nacre)
Aragonite (CaCO3) - Biogenic Mineral
mineral
Mother of Pearl (Nacre)
Aragonite with Conchiolin (CaCO3)
mineral
Pearl (as a biogenic mineral/gemstone)
Calcium Carbonate (mostly Aragonite), CaCO3
mineral
Sea Shell Fragment (Calcium Carbonate)
Aragonite / Calcite (CaCO3)
mineral
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
mineral
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
mineral
Human Skin (Epidermis/Dermis)
Integumentary tissue (High content of hydroxyapatite in bones, though the surface is biological)
Mineral-like biological tissue
Precious Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
mineral