Rock Identifier

Category

Organic (Geological Interest)

Browse organic (geological interest) specimens identified by the Rock Identifier community.

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Chert (Yellow or Brown Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow or Brown Jasper)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Pearl necklace (Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)) — gemstone

Pearl necklace

Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)

Sandstone with Quartz Crystal Infill (Quartz-cemented quartz arenite) — sedimentary

Sandstone with Quartz Crystal Infill

Quartz-cemented quartz arenite

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Ironstone Nodules in Chalk/Limestone (Limonite/Goethite concretions (FeO(OH)·nH2O) in Calcium Carbonate matrix (CaCO3)) — sedimentary

Ironstone Nodules in Chalk/Limestone

Limonite/Goethite concretions (FeO(OH)·nH2O) in Calcium Carbonate matrix (CaCO3)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — metamorphic

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Fossilized Coral (Rugosa / Scleractinia (Agatized or Calcitized Coral)) — fossil

Fossilized Coral

Rugosa / Scleractinia (Agatized or Calcitized Coral)

Petrified Wood (Silicified Wood (primarily SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, SiO2)) — mineral

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Fossilized tooth fragment, possibly a mammalian tooth (Indeterminate fossil tooth; enamel and dentine, taxon not identifiable from this fragment) — fossil

Fossilized tooth fragment, possibly a mammalian tooth

Indeterminate fossil tooth; enamel and dentine, taxon not identifiable from this fragment

Pyrite (Pyrite (Iron sulfide, FeS₂)) — Mineral

Pyrite

Pyrite (Iron sulfide, FeS₂)

Chert (White Chert / Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert / Flint

Cryptocrystalline Quartz (SiO2)

Chert (Green variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Green variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often colloquially referred to as Flint) (Chert (Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (often colloquially referred to as Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Chert (specifically Flint or Gray Chert) (Silicon Dioxide (Microcrystalline Quartz), SiO2) — sedimentary

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (Microcrystalline Quartz), SiO2

Chert (vuggy variety) (Microcrystalline silica (SiO2)) — sedimentary

Chert (vuggy variety)

Microcrystalline silica (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Chert (specifically Yellow Jasper variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (specifically Yellow Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Jasper/Agate variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Chert (Flint) (Silicon dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Sandstone (Arenite (SiO2 composed primarily of quartz)) — sedimentary

Sandstone

Arenite (SiO2 composed primarily of quartz)

Petrified Wood (Silicified Wood (SiO2 permineralization)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 permineralization)

Blue-green serpentinite (likely copper-stained) (Serpentinite; chiefly serpentine-group minerals, commonly with malachite/chrysocolla or other copper minerals) — metamorphic

Blue-green serpentinite (likely copper-stained)

Serpentinite; chiefly serpentine-group minerals, commonly with malachite/chrysocolla or other copper minerals

Chert Arrowhead (Projectile Point) (Microcrystalline Quartz (Chert or Flint)) — sedimentary

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Petrified Wood (Silicified Wood (primarily SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily SiO2)

Ammonite Fossil (Small Pyritized or Calcitized Internal Mold) (Ammonoidea) — sedimentary

Ammonite Fossil (Small Pyritized or Calcitized Internal Mold)

Ammonoidea

Petrified Wood (Silicified Wood (SiO2 permineralization)) — fossil

Petrified Wood

Silicified Wood (SiO2 permineralization)

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Fossilized Shark Tooth (Eroded) (Carcharodon sp. or Otodus sp. fragment (likely)) — fossil

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

Limestone (with weathering rind) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (with weathering rind)

Calcium Carbonate (CaCO3)

Honey calcite (Calcite (calcium carbonate, CaCO₃)) — mineral

Honey calcite

Calcite (calcium carbonate, CaCO₃)

Chert (Flint variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint variety)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Chert (Commonly known as Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Commonly known as Flint)

Microcrystalline Quartz (SiO2)

Tumbled brown jasper (Microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained) — sedimentary

Tumbled brown jasper

Microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained

Fossilized Shark Tooth (Chondrichthyes (Class)) — fossil

Fossilized Shark Tooth

Chondrichthyes (Class)