Rock Identifier

Category

Mineral (Biogenic Replacement)

Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.

Fossilized Shark Tooth (Cretaceous to Neogene) (Elasmobranchii dental fossil (likely Squalicorax or similar species)) — mineral (biogenic replacement)

Fossilized Shark Tooth (Cretaceous to Neogene)

Elasmobranchii dental fossil (likely Squalicorax or similar species)

mineral (biogenic replacement)

Fossilized Tooth Fragment (Vertebrate Fossil (Mammalia indet.)) — fossil

Fossilized Tooth Fragment

Vertebrate Fossil (Mammalia indet.)

Chert (Jasper variation) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Fossilized Bone (Petrified Bone / Biogenic Sedimentary) — fossil

Fossilized Bone

Petrified Bone / Biogenic Sedimentary

Stromatolite (Laminated biogenic sedimentary structure (Cyanobacteria)) — sedimentary

Stromatolite

Laminated biogenic sedimentary structure (Cyanobacteria)

Chert (Pebble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Pebble)

Silicon Dioxide (SiO2)

Chert (Nodule) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Stromatolite (Biogenic sedimentary structure (Stromatolite)) — fossil

Stromatolite

Biogenic sedimentary structure (Stromatolite)

Fossilized Tooth (Vertebrate Fossilized Tooth (Mineralized Biogenic Material)) — fossil

Fossilized Tooth

Vertebrate Fossilized Tooth (Mineralized Biogenic Material)

Fossil gastropod shell (Calcareous mollusk shell, chiefly aragonite or calcite (likely a large marine gastropod)) — fossil

Fossil gastropod shell

Calcareous mollusk shell, chiefly aragonite or calcite (likely a large marine gastropod)

Fossil oyster shell (Ostrea or Exogyra sp. (identification uncertain)) — fossil

Fossil oyster shell

Ostrea or Exogyra sp. (identification uncertain)

Chert or flint fragment (Microcrystalline quartz (SiO₂), commonly chalcedony with cryptocrystalline quartz) — sedimentary

Chert or flint fragment

Microcrystalline quartz (SiO₂), commonly chalcedony with cryptocrystalline quartz

Chert (likely chalcedony-rich flint) (Microcrystalline quartz, SiO₂ (quartz/chalcedony)) — sedimentary

Chert (likely chalcedony-rich flint)

Microcrystalline quartz, SiO₂ (quartz/chalcedony)

Likely fossilized shell or carbonate concretion (Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)) — fossil

Likely fossilized shell or carbonate concretion

Indeterminate biogenic calcium carbonate, commonly calcite (CaCO₃)

Chert (Flint) (Microcrystalline or cryptocrystalline quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or cryptocrystalline quartz (SiO2)

Chert / Flint (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Flint

Microcrystalline Quartz (SiO2)

Spiny Oyster Shell (Spondylus (Calcium Carbonate, CaCO3)) — mineral

Spiny Oyster Shell

Spondylus (Calcium Carbonate, CaCO3)

Weathered fossil shell fragment (Likely molluscan shell, composed mainly of calcium carbonate (aragonite or calcite); exact taxon is indeterminate from the image) — fossil

Weathered fossil shell fragment

Likely molluscan shell, composed mainly of calcium carbonate (aragonite or calcite); exact taxon is indeterminate from the image

Chert (Flint / Chalcedony pebble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint / Chalcedony pebble)

Silicon Dioxide (SiO2)

Chert (Iron-stained) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and Fossiliferous Limestone) (Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert (and Fossiliferous Limestone)

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Fossiliferous Chert (Cryptocrystalline quartz (SiO2) with biogenic inclusions) — sedimentary

Fossiliferous Chert

Cryptocrystalline quartz (SiO2) with biogenic inclusions

Limestone with Chert (Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions) — sedimentary

Limestone with Chert

Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions

Chert (and associated Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and associated Flint)

Silicon Dioxide (SiO2)

Weathered chert or siliceous limestone (Microcrystalline quartz (SiO₂), possibly replacing or cementing carbonate rock) — sedimentary

Weathered chert or siliceous limestone

Microcrystalline quartz (SiO₂), possibly replacing or cementing carbonate rock

Polished brown flint/chert nodule (Microcrystalline quartz (SiO₂), commonly called flint or chert) — sedimentary

Polished brown flint/chert nodule

Microcrystalline quartz (SiO₂), commonly called flint or chert

Coral limestone / fossil coral (Biogenic calcium carbonate, chiefly aragonite or calcite (CaCO₃); likely fossilized colonial coral) — fossil

Coral limestone / fossil coral

Biogenic calcium carbonate, chiefly aragonite or calcite (CaCO₃); likely fossilized colonial coral

Polished fossil shell or bone fragment (tentative) (Indeterminate biogenic carbonate or fossilized bone; possibly a small gastropod/bivalve fragment) — fossil

Polished fossil shell or bone fragment (tentative)

Indeterminate biogenic carbonate or fossilized bone; possibly a small gastropod/bivalve fragment

Kidney Stone (Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)) — mineral

Kidney Stone

Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)

Weathered chert or silicified limestone nodule (Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃)) — sedimentary

Weathered chert or silicified limestone nodule

Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃)

$Flint (chert), likely a worked or fractured nodule (Microcrystalline quartz/chalcedony (SiO₂)) — sedimentary$

Flint (chert), likely a worked or fractured nodule

Microcrystalline quartz/chalcedony (SiO₂)

Fossiliferous Chert (with Fossil Shells) (Silicon Dioxide (SiO2) with biogenic inclusions) — sedimentary

Fossiliferous Chert (with Fossil Shells)

Silicon Dioxide (SiO2) with biogenic inclusions

Chert or flint with chalcedony/quartz veins (Microcrystalline silica: primarily quartz (SiO₂), including chalcedony; possible fossiliferous limestone or silicified material) — sedimentary

Chert or flint with chalcedony/quartz veins

Microcrystalline silica: primarily quartz (SiO₂), including chalcedony; possible fossiliferous limestone or silicified material

Chert (Chert (microcrystalline quartz, SiO2)) — sedimentary

Chert

Chert (microcrystalline quartz, SiO2)

Pearl (Aragonite (CaCO3) with Conchiolin) — mineral

Pearl

Aragonite (CaCO3) with Conchiolin

Fossilized shell or bone fragment (Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone) — fossil

Fossilized shell or bone fragment

Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone

Seashell (Calcium Carbonate) (Calcium Carbonate (CaCO3)) — mineral

Seashell (Calcium Carbonate)

Calcium Carbonate (CaCO3)

Pearl (as a Biogenic Mineral) (Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3) — mineral

Pearl (as a Biogenic Mineral)

Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3

Abalone Shell (Nacre) (Aragonite (CaCO3) - Biogenic Mineral) — mineral

Abalone Shell (Nacre)

Aragonite (CaCO3) - Biogenic Mineral

Cleavable Calcite (Calcium Carbonate (CaCO3)) — mineral

Cleavable Calcite

Calcium Carbonate (CaCO3)

Brachiopod Fossil (Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)) — sedimentary

Brachiopod Fossil

Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)