Rock Identifier

Category

Organic (Non Geological)

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

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

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

Black Obsidian

Volcanic Glass (SiO2 + impurities)

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)

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)

Limonite (Yellow Ochre) (Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)) — mineral

Limonite (Yellow Ochre)

Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)

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

Obsidian with Mahogany Phasing (Volcanic Glass (SiO2 + Fe2O3)) — igneous

Obsidian with Mahogany Phasing

Volcanic Glass (SiO2 + Fe2O3)

Rounded gray river pebble, likely basalt or andesite (Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)) — igneous

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)

Barite (Barium Sulfate (BaSO4)) — mineral

Barite

Barium Sulfate (BaSO4)

Quartzite (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite

Metamorphic Quartzite (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)

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

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Polished orbicular granite (Orbicular granite, commonly quartz–feldspar–biotite granite with orbicules) — igneous

Polished orbicular granite

Orbicular granite, commonly quartz–feldspar–biotite granite with orbicules

Quartzite Pebble with Pyrite Coating (SiO2 (Quartz) with FeS2 (Pyrite) inclusions or surface coating) — metamorphic

Quartzite Pebble with Pyrite Coating

SiO2 (Quartz) with FeS2 (Pyrite) inclusions or surface coating

Sandstone Concretion (Sedimentary Clastic Rock (Silicate-rich)) — sedimentary

Sandstone Concretion

Sedimentary Clastic Rock (Silicate-rich)

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

Fossilized Shark Tooth (Eroded)

Carcharodon sp. or Otodus sp. fragment (likely)

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

Sandstone

Arenite (SiO2 composed primarily of quartz)

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)

Water-worn dark beach pebble (Likely fine-grained basalt or dolerite (diabase)) — igneous

Water-worn dark beach pebble

Likely fine-grained basalt or dolerite (diabase)

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)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Blue faceted gemstones, likely blue sapphire (Corundum (Al₂O₃), blue varieties colored chiefly by iron and titanium) — gemstone

Blue faceted gemstones, likely blue sapphire

Corundum (Al₂O₃), blue varieties colored chiefly by iron and titanium

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

Honey calcite

Calcite (calcium carbonate, CaCO₃)