Rock Identifier

Category

Mineral (Biogenic Replacement)

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

Jasper (Microcrystalline quartz (SiO2)) — sedimentary

Jasper

Microcrystalline quartz (SiO2)

Magnetite / Hematite mix (Iron Ore) (Fe3O4 (Magnetite) / Fe2O3 (Hematite)) — mineral

Magnetite / Hematite mix (Iron Ore)

Fe3O4 (Magnetite) / Fe2O3 (Hematite)

Fossilized bone fragment (Mineralized vertebrate bone, commonly hydroxyapatite partly replaced by silica or calcite) — fossil

Fossilized bone fragment

Mineralized vertebrate bone, commonly hydroxyapatite partly replaced by silica or calcite

Weathered fossil fragment, possibly bone (Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)) — fossil

Weathered fossil fragment, possibly bone

Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)

Fossilized shell or small fossil fragment (Indeterminate fossil; possibly a partial gastropod or bivalve, mineralized with calcite) — fossil

Fossilized shell or small fossil fragment

Indeterminate fossil; possibly a partial gastropod or bivalve, mineralized with calcite

Fossilized Bivalve Shell (Bivalvia (Phylum Mollusca)) — fossil

Fossilized Bivalve Shell

Bivalvia (Phylum Mollusca)

Brown Quartz (Jasper or Chert) (Silicon Dioxide (SiO2)) — sedimentary

Brown Quartz (Jasper or Chert)

Silicon Dioxide (SiO2)

Polished red jasper (Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides) — mineral

Polished red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Fossil shell fragment (Likely a fossilized brachiopod or bivalve; exact taxon cannot be determined from the image) — fossil

Fossil shell fragment

Likely a fossilized brachiopod or bivalve; exact taxon cannot be determined from the image

Fossilized Bone (Permineralized Vertebrate Bone) — fossil

Fossilized Bone

Permineralized Vertebrate Bone

Shark Tooth Fossil (Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)) — fossil

Shark Tooth Fossil

Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)

Turritella Fossil (Turritella (Class Gastropoda, Family Turritellidae)) — fossil

Turritella Fossil

Turritella (Class Gastropoda, Family Turritellidae)

Fossilized Brachiopod (Brachiopoda (Phylum)) — fossil

Fossilized Brachiopod

Brachiopoda (Phylum)

Chert (with Limestone and Iron Oxide staining) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Limestone and Iron Oxide staining)

Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Banded Jasper (Silicate Mineral (Microcrystalline Quartz / SiO2)) — sedimentary

Banded Jasper

Silicate Mineral (Microcrystalline Quartz / SiO2)

Calcite (Calcite (Mineral; CaCO₃)) — Mineral

Calcite

Calcite (Mineral; CaCO₃)

Fossilized bivalve shell fragment (Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized) — fossil

Fossilized bivalve shell fragment

Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized

Fossil Brachiopod (Phylum Brachiopoda) — fossil

Fossil Brachiopod

Phylum Brachiopoda

Fossilized Megalodon Tooth Fragment (Otodus megalodon (Carcharocles megalodon fossil)) — sedimentary

Fossilized Megalodon Tooth Fragment

Otodus megalodon (Carcharocles megalodon fossil)

Carnelian (Carnelian (Cryptocrystalline variety of Quartz, SiO2)) — mineral

Carnelian

Carnelian (Cryptocrystalline variety of Quartz, SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Pyrite (Cube variety) (Iron Sulfide (FeS2)) — mineral

Pyrite (Cube variety)

Iron Sulfide (FeS2)

Chalcedony (Agate) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Rhodonite (Manganese Silicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Jasper (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper

Silicon Dioxide (SiO2) with impurities

Fossilized Brachiopod (Phylum Brachiopoda (replaced by Calcite/CaCO3)) — sedimentary

Fossilized Brachiopod

Phylum Brachiopoda (replaced by Calcite/CaCO3)

Petrified wood (Silicified wood; commonly quartz (SiO₂) replacing wood tissue) — fossil

Petrified wood

Silicified wood; commonly quartz (SiO₂) replacing wood tissue

Fossil bivalve shell (Fossilized or partially mineralized bivalve; exact genus cannot be determined from the image) — fossil

Fossil bivalve shell

Fossilized or partially mineralized bivalve; exact genus cannot be determined from the image

Fossilized Bone (Permineralized Vertebrate Bone) — fossil

Fossilized Bone

Permineralized Vertebrate Bone

Fossilized Bone Chunk (likely Dinosaur or Large Mammal) (Permineralized Fossil Bone) — sedimentary

Fossilized Bone Chunk (likely Dinosaur or Large Mammal)

Permineralized Fossil Bone

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Chert (Chert (SiO2)) — sedimentary

Chert

Chert (SiO2)

Fossilized Coral (Petoskey Stone or Rugose Coral) (Antophyllum (Hexagonaria) or Scleractinia (CaCO3)) — sedimentary

Fossilized Coral (Petoskey Stone or Rugose Coral)

Antophyllum (Hexagonaria) or Scleractinia (CaCO3)

Chert (Flint variety) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint variety)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Green Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Green Jasper

Jasper (Silicon Dioxide, SiO2)

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

Chert (Flint) Pebble

Microcrystalline Quartz (SiO2)

Fossilized gastropod (likely nerite or related sea snail) (Gastropoda; shell composed originally of aragonite/calcite, commonly replaced or infilled by calcite) — fossil

Fossilized gastropod (likely nerite or related sea snail)

Gastropoda; shell composed originally of aragonite/calcite, commonly replaced or infilled by calcite

Chert (Septarian or Banded Nodular Variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Septarian or Banded Nodular Variety)

Microcrystalline Quartz (SiO2)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Pyrite (Pseudomorph) (Iron Sulfide (FeS2)) — mineral

Pyrite (Pseudomorph)

Iron Sulfide (FeS2)