Rock Identifier

Category

Organic (Non Geological)

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

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

Limestone (or Sandstone)

Calcium Carbonate (CaCO3) / Silica (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily 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

Chert (Nodule) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (Nodule)

Chert (Cryptocrystalline Silica, SiO2)

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

Sandstone with Quartz Crystal Infill

Quartz-cemented quartz arenite

Black Obsidian (Volcanic Glass (SiO2 with impurities)) — igneous

Black Obsidian

Volcanic Glass (SiO2 with impurities)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Siltstone River Pebble (Siltstone (primarily composed of silt-sized particles)) — sedimentary

Siltstone River Pebble

Siltstone (primarily composed of silt-sized particles)

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

Stromatolite

Biogenic Sedimentary Rock (composed predominantly of CaCO3)

Black Obsidian (Amorphous volcanic glass (SiO2 + impurities)) — igneous

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

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

Limestone

Sedimentary rock composed mainly of calcite (CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Coal (Bituminous Coal / Anthracite) — sedimentary

Coal

Bituminous Coal / Anthracite

Black Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Black Obsidian

Volcanic Glass (predominantly SiO2)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Mudstone variety with Oxidation)

Silicon dioxide (SiO2)

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

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

Milky quartz (rough quartz specimen) (Quartz, silicon dioxide (SiO₂)) — mineral

Milky quartz (rough quartz specimen)

Quartz, silicon dioxide (SiO₂)

Obsidian (Obsidian (volcanic glass; primarily SiO2)) — igneous

Obsidian

Obsidian (volcanic glass; primarily SiO2)

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

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Obsidian (Obsidian (volcanic glass), amorphous SiO2 + impurities) — igneous

Obsidian

Obsidian (volcanic glass), amorphous SiO2 + impurities

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)

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

Petrified Wood

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

Obsidian (Volcanic glass (mainly SiO2)) — Igneous

Obsidian

Volcanic glass (mainly SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (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)

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)

Slag Glass (Anthropogenic Amorphous Silicon Dioxide) — mineral

Slag Glass

Anthropogenic Amorphous Silicon Dioxide

Anthracite Coal (Anthracite (Carbon Content: 86%-97%)) — metamorphic

Anthracite Coal

Anthracite (Carbon Content: 86%-97%)

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

Chert (Yellow or Brown Jasper)

Microcrystalline Quartz (SiO2)

Obsidian (Obsidian (Extrusive Volcanic Glass)) — igneous

Obsidian

Obsidian (Extrusive Volcanic Glass)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Mahogany Obsidian (Obsidian (Volcanic Glass with Hematite inclusions)) — igneous

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite inclusions)

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

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)