Rock Identifier

Category

Organic (Sedimentary Context)

Browse organic (sedimentary context) specimens identified by the Rock Identifier community.

Ironstone Concretion (Siderite or Hematite Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite Concretion

Gneiss (Gneiss (pronounced 'nice')) — Metamorphic Rock

Gneiss

Gneiss (pronounced 'nice')

Metamorphic Rock

Sandy Ironstone (Ferruginous Sandstone) — sedimentary

Sandy Ironstone

Ferruginous Sandstone

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Chert (specifically Red Chert or Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Red Chert or Jasper)

Microcrystalline Quartz (SiO2)

Chert (Jasper variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Banded Chert (or Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (or Flint)

Microcrystalline Quartz (SiO2)

Chert (Brown variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Brown variety)

Silicon Dioxide (SiO2)

Fossiliferous Limestone (Crinoidal) (Calcium Carbonate (CaCO3) - Limestone containing bioclasts) — sedimentary

Fossiliferous Limestone (Crinoidal)

Calcium Carbonate (CaCO3) - Limestone containing bioclasts

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Quartz Variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Quartz Variety)

Silicon Dioxide (SiO2)

Chert (often called Flint or Jasper) (Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Chert Pebble with Quartz Veining (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Banded Chert (River Siltstone) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (River Siltstone)

Microcrystalline Quartz (SiO2)

Glauconitic Sandstone (Greensand) (Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

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

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

Fossil Coral (Favosites) (Favosites (Order: Tabulata, Phylum: Cnidaria)) — sedimentary

Fossil Coral (Favosites)

Favosites (Order: Tabulata, Phylum: Cnidaria)

Chert (Black Chert/Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Black Chert/Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (containing Brachiopods) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone (containing Brachiopods)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Pink Opal (Common Opal) (Amorphous Hydrated Silica (SiO2·nH2O)) — mineral

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Shale (Shale (clastic sedimentary rock)) — Sedimentary

Shale

Shale (clastic sedimentary rock)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified wood (primarily SiO2)

Baltic Amber (Butterscotch or Egg Yolk Variety) (Succinite (chemical formula: C10H16O)) — Organic Gemstone (not a rock or mineral)

Baltic Amber (Butterscotch or Egg Yolk Variety)

Succinite (chemical formula: C10H16O)

Organic Gemstone (not a rock or mineral)

Amber (Succinite) — mineraloid

Amber

Succinite

Fossil Coral (Rugosa or Solitary Coral) (Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)) — sedimentary

Fossil Coral (Rugosa or Solitary Coral)

Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)

Banded Chert (Flint/Jasper variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Chert / Flint (Cryptocrystalline Quartz (Silicon Dioxide, SiO2)) — sedimentary

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Chert (Nodule / Geode fragment) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood (principally Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (principally Silicon Dioxide, SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Sandstone (likely Fossilized Wood or Concrete Simulacrum) (Arenite / Silicified Wood / Anthropogenic Concrete) — sedimentary

Sandstone (likely Fossilized Wood or Concrete Simulacrum)

Arenite / Silicified Wood / Anthropogenic Concrete

Chert (with Liesegang Banding) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (with Liesegang Banding)

Microcrystalline quartz (SiO2)

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

Petrified Wood

Silicified Wood (SiO2 permineralization)

Water and Silt (Sedimentary Environment) (Suspended Sediment / H2O (dihydrogen monoxide)) — sedimentary

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Amber (Succinite (a fossilized organic resin containing succinic acid)) — mineraloid

Amber

Succinite (a fossilized organic resin containing succinic acid)

Crushed Limestone (Calcite-rich Sedimentary Rock (CaCO3)) — sedimentary

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)

Shale (Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)) — sedimentary

Shale

Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)

Limestone with Quartz/Calcite Veins (Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)) — sedimentary

Limestone with Quartz/Calcite Veins

Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)

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

Petrified Wood

Silicified Wood (primarily SiO2)