Rock Identifier

Category

Organic (Geological Relative)

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

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Small seashell fossil or shell fragment (Likely calcium-carbonate shell material, chiefly aragonite or calcite; exact species indeterminate) — fossil

Small seashell fossil or shell fragment

Likely calcium-carbonate shell material, chiefly aragonite or calcite; exact species indeterminate

Banded sandstone pebble (Quartz-rich lithic sandstone; exact provenance and composition require testing) — sedimentary

Banded sandstone pebble

Quartz-rich lithic sandstone; exact provenance and composition require testing

Quartz Geode (Silicon Dioxide (SiO2)) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Graphite (Graphite (Native Carbon, C)) — metamorphic

Graphite

Graphite (Native Carbon, C)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (Cherty Flint/Jasper variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Cherty Flint/Jasper variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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)

Chert (Chert Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Graphite (Graphite (C)) — mineral

Graphite

Graphite (C)

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)

Fossiliferous Shale Matrix (Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments) — sedimentary

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Amber (Succinite (C10H16O)) — gemstone

Amber

Succinite (C10H16O)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Aquamarine (Beryl (Be3Al2Si6O18)) — Mineral

Aquamarine

Beryl (Be3Al2Si6O18)

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

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

Granite (Granite (a felsic intrusive igneous rock)) — Igneous Rock

Granite

Granite (a felsic intrusive igneous 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)

Sand Tiger Shark Tooth (Carcharias taurus) — fossil

Sand Tiger Shark Tooth

Carcharias taurus

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)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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)

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

Moss Agate

Silicon Dioxide (Chalcedony variety)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

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

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

Honeycomb Coral Fossil

Favosites (extinct genus of tabulate coral)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Chert (Arrowhead/Tool variety)

Microcrystalline Quartz (SiO2)

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

Chert (Arrowhead variety)

Chert (SiO2)

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

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

Chert Fossil (Pebble)

Microcrystalline Quartz (SiO2) with biogenic inclusions

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)

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

Amber

Succinite (fossilized resin); C10H16O