Rock Identifier

Category

Organic (Geological Interest)

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

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)

Quartz (in a rock matrix) (Quartz (SiO2)) — mineral

Quartz (in a rock matrix)

Quartz (SiO2)

Stromatolite (Biogenic Sedimentary Rock (composed predominantly of CaCO3)) — sedimentary

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

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)

Limestone (Sedimentary rock composed mainly of calcite (CaCO3)) — sedimentary

Limestone

Sedimentary rock composed mainly of calcite (CaCO3)

Limestone (or Sandstone) (Calcium Carbonate (CaCO3) / Silica (SiO2)) — sedimentary

Limestone (or Sandstone)

Calcium Carbonate (CaCO3) / Silica (SiO2)

Oak-grain Laminate (Industrial/Decorative Furniture Finish) (Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)) — not a rock (synthetic material)

Oak-grain Laminate (Industrial/Decorative Furniture Finish)

Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)

not a rock (synthetic material)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Jasper/Mudstone variety with Oxidation) (Silicon dioxide (SiO2)) — sedimentary

Chert (Jasper/Mudstone variety with Oxidation)

Silicon dioxide (SiO2)

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)

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

Chert (Yellow or Brown Jasper)

Microcrystalline Quartz (SiO2)

Coal (Bituminous Coal / Anthracite) — sedimentary

Coal

Bituminous Coal / Anthracite

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

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

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

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Concrete or asphalt-like aggregate surface with a dark fragment (Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock) — sedimentary

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

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

Pearl necklace

Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Pearl (Aragonite / Calcium Carbonate (CaCO3)) — mineral

Pearl

Aragonite / Calcium Carbonate (CaCO3)

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)

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)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

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

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Pyrite

Pyrite (Iron sulfide, FeS₂)

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

Chert (often colloquially referred to as Flint)

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

Chert (vuggy variety)

Microcrystalline silica (SiO2)

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

Chert (specifically Yellow Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert (specifically Flint or Gray Chert)

Silicon Dioxide (Microcrystalline Quartz), SiO2

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

Chert (Iron-stained)

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)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)