Rock Identifier

Category

Organic (Non Geological)

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

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Chert (with Quartz vein) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (with Quartz vein)

Chert (Silicon Dioxide, SiO2)

Limestone (Chalk / Calcite Rock) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (Chalk / Calcite Rock)

Calcium Carbonate (CaCO3)

Sandstone (Sedimentary Clastic Rock (Quartz Arenite)) — sedimentary

Sandstone

Sedimentary Clastic Rock (Quartz Arenite)

Petrified Wood (Silicon Dioxide (SiO2) permineralized organic matter) — sedimentary

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

Gold Sheen Obsidian (Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)) — igneous

Gold Sheen Obsidian

Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)

Obsidian (Volcanic Glass (Amorphous Silica)) — igneous

Obsidian

Volcanic Glass (Amorphous Silica)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of cellulose)) — fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of cellulose)

Petrified Wood (Silicified wood (principally SiO2)) — sedimentary

Petrified Wood

Silicified wood (principally SiO2)

Sand Tiger Shark Tooth (Carcharias taurus) — fossil

Sand Tiger Shark Tooth

Carcharias taurus

Likely obsidian (possibly tektite or slag glass) (Volcanic glass; primarily SiO₂, noncrystalline) — igneous

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Obsidian (Obsidian (principally SiO2 - Silicon Dioxide)) — igneous

Obsidian

Obsidian (principally SiO2 - Silicon Dioxide)

Obsidian (Obsidian (principally SiO2)) — igneous

Obsidian

Obsidian (principally SiO2)

Petoskey Stone (Hexagonaria percarinata (Calcite / CaCO3)) — fossil

Petoskey Stone

Hexagonaria percarinata (Calcite / CaCO3)

Pale rounded quartz-rich pebble, likely quartzite (Quartzite (mostly microcrystalline SiO₂), possibly quartz-rich sandstone or vein quartz) — metamorphic

Pale rounded quartz-rich pebble, likely quartzite

Quartzite (mostly microcrystalline SiO₂), possibly quartz-rich sandstone or vein quartz

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Moss Agate and Hematite (Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)) — mineral

Moss Agate and Hematite

Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Moss Agate (Silicon Dioxide (Chalcedony variety)) — mineral

Moss Agate

Silicon Dioxide (Chalcedony variety)

Obsidian (Obsidian (Volcanic Glass)) — igneous

Obsidian

Obsidian (Volcanic Glass)

Slag Glass (Cullet) (Amorphous Silica / Glass residue) — Man-made byproduct (Non-geological)

Slag Glass (Cullet)

Amorphous Silica / Glass residue

Man-made byproduct (Non-geological)

Rounded brown sandstone or weathered river cobble (Likely quartz-rich sandstone; exact identification requires a fresh surface and tests) — sedimentary

Rounded brown sandstone or weathered river cobble

Likely quartz-rich sandstone; exact identification requires a fresh surface and tests

Obsidian (Volcanic Glass (predominantly SiO2)) — igneous

Obsidian

Volcanic Glass (predominantly SiO2)

Quartzite (Metamorphic Quartz Sandstone) — metamorphic

Quartzite

Metamorphic Quartz Sandstone

Honeycomb Coral Fossil (Favosites (extinct genus of tabulate coral)) — fossil

Honeycomb Coral Fossil

Favosites (extinct genus of tabulate coral)

Fossilized tooth, likely a mammalian tooth fragment (Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth) — fossil

Fossilized tooth, likely a mammalian tooth fragment

Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth

Obsidian (Volcanic Glass (SiO2, usually >70% silica content)) — Igneous

Obsidian

Volcanic Glass (SiO2, usually >70% silica content)

Obsidian (Obsidian (Volcanic Glass, primarily SiO2)) — igneous

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Chert (Arrowhead/Tool variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2)

Mineral / Fossil

Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)) — Igneous

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Chert (Arrowhead variety) (Chert (SiO2)) — sedimentary

Chert (Arrowhead variety)

Chert (SiO2)

Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)) — Igneous

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Obsidian (Volcanic Glass (SiO2 rich)) — Igneous

Obsidian

Volcanic Glass (SiO2 rich)

Chert Fossil (Pebble) (Microcrystalline Quartz (SiO2) with biogenic inclusions) — sedimentary

Chert Fossil (Pebble)

Microcrystalline Quartz (SiO2) with biogenic inclusions

Fossilized Echinoid (Sea Urchin) (Echinoidea (Class) - Often found as Micraster or Clypeaster specimens) — sedimentary

Fossilized Echinoid (Sea Urchin)

Echinoidea (Class) - Often found as Micraster or Clypeaster specimens

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

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (and Petrified Wood) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Petrified Wood)

Silicon Dioxide (SiO2)

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

Honey calcite (orange calcite)

Calcite, calcium carbonate (CaCO₃)