Rock Identifier

Category

Organic (Geological Interest)

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

Moss Agate (Silicon Dioxide with inclusions (SiO2)) — mineral

Moss Agate

Silicon Dioxide with inclusions (SiO2)

Mixed Quartz and Jasper Pebbles (Silicon Dioxide (SiO2)) — Mineral

Mixed Quartz and Jasper Pebbles

Silicon Dioxide (SiO2)

Travertine (Tufa) (Chemical Limestone (CaCO3)) — sedimentary

Travertine (Tufa)

Chemical Limestone (CaCO3)

Fossilized Shark Tooth (Chondrichthyes tooth) — fossil

Fossilized Shark Tooth

Chondrichthyes tooth

Red Jasper (Silicon Dioxide (SiO2) with Iron Oxide inclusions) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Chert (Brown variety / Common Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Brown variety / Common Jasper)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper locally) (Chert (Microcrystalline Quartz, Formula: SiO2)) — sedimentary

Chert (often called Flint or Jasper locally)

Chert (Microcrystalline Quartz, Formula: SiO2)

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

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Sand Tiger Shark Tooth (Carcharias taurus) — fossil

Sand Tiger Shark Tooth

Carcharias taurus

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

Petrified Wood

Silicified Wood (primarily SiO2)

Biological Bone (Patella/Knee) (Patella (part of the Human Skeletal System)) — Organic Structure (Not a Rock)

Biological Bone (Patella/Knee)

Patella (part of the Human Skeletal System)

Organic Structure (Not a Rock)

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)

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

Petoskey Stone

Hexagonaria percarinata (Calcite / CaCO3)

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)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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)

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

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

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

Honeycomb Coral Fossil

Favosites (extinct genus of tabulate coral)

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

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)

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

Chert (Arrowhead variety)

Chert (SiO2)

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

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

Chert Fossil (Pebble)

Microcrystalline Quartz (SiO2) with biogenic inclusions

Coal (most likely Bituminous or Anthracite) (Coal (organic sedimentary rock)) — Sedimentary

Coal (most likely Bituminous or Anthracite)

Coal (organic sedimentary rock)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Honey calcite (orange calcite)

Calcite, calcium carbonate (CaCO₃)

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)

Chert (Flint) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Amber (Succinite (fossilized resin); C10H16O) — mineraloid

Amber

Succinite (fossilized resin); C10H16O

Chert (variations include Flint or Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Fossil Coral (Petoskey / Horn Coral Sliced Button) (Scleractinia / Rugosa (Silurian-Devonian Anthozoa)) — fossil

Fossil Coral (Petoskey / Horn Coral Sliced Button)

Scleractinia / Rugosa (Silurian-Devonian Anthozoa)

Jasper (Silicon Dioxide (SiO2) with iron oxide impurities) — sedimentary

Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Chert (variations include Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)