Rock Identifier

Category

Organic (Sedimentary Context)

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

Learn about Organic (Sedimentary Context) in the encyclopedia

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Oil Shale

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)

Likely petrified wood or silicified fossil fragment (Silicified wood; predominantly microcrystalline quartz (SiO₂)) — fossil

Likely petrified wood or silicified fossil fragment

Silicified wood; predominantly microcrystalline quartz (SiO₂)

Fossilized Horn Coral (Rugosa (Rugose Coral)) — fossil

Fossilized Horn Coral

Rugosa (Rugose Coral)

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

Chert (Iron-stained)

Chert (primarily Microcrystalline Quartz, SiO2)

Ferruginous Quartz (Silicon Dioxide (SiO2) with Hematite/Limonite impurities) — mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Iron Ore / Hematite / Ironstone Nodule (Hematite / Goethite (Fe2O3 / FeO(OH))) — sedimentary

Iron Ore / Hematite / Ironstone Nodule

Hematite / Goethite (Fe2O3 / FeO(OH))

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)

Shale (Shale (clastic sedimentary rock)) — Sedimentary

Shale

Shale (clastic sedimentary rock)

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

Pink Opal (Common Opal)

Amorphous Hydrated Silica (SiO2·nH2O)

Fossil-bearing sedimentary rock, possibly fossil wood or bone (Indeterminate silicified/carbonate fossil in sandstone or mudstone) — fossil

Fossil-bearing sedimentary rock, possibly fossil wood or bone

Indeterminate silicified/carbonate fossil in sandstone or mudstone

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Coquina (Biogenic Limestone (Calcium Carbonate - CaCO3)) — sedimentary

Coquina

Biogenic Limestone (Calcium Carbonate - CaCO3)

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

Chert (with Quartz vein)

Chert (Silicon Dioxide, SiO2)

Likely tumbled jasper or chert specimens (Microcrystalline quartz (SiO₂), commonly jasper/chert; exact identification is uncertain from the photograph) — sedimentary

Likely tumbled jasper or chert specimens

Microcrystalline quartz (SiO₂), commonly jasper/chert; exact identification is uncertain from the photograph

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

Petrified Wood

Silicified wood (principally SiO2)

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

Banded Chert / Flint

Microcrystalline Quartz (SiO2)

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)

Chert (with Calcite Veining) (Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) veins) — sedimentary

Chert (with Calcite Veining)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) veins

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

Banded Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified wood (principally Silicon Dioxide, SiO2)

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

Chert (Nodule / Geode fragment)

Microcrystalline Quartz (SiO2)

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

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily 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

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Fe2O3 cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

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

Chert (with Liesegang Banding)

Microcrystalline quartz (SiO2)

Chert (Limestone-hosted Pebble) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Limestone-hosted Pebble)

Sedimentary Cryptocrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (SiO2 permineralization)

Amber (Succinite) — mineraloid

Amber

Succinite

Fossilized Bark (Lepidodendron / Sigillaria fossil impression) — fossil

Fossilized Bark

Lepidodendron / Sigillaria fossil impression

Slate (Metamorphic Mudstone / Shale) — metamorphic

Slate

Metamorphic Mudstone / Shale

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)

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

Shale

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

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

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

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

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

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

Travertine (Tufa)

Chemical Limestone (CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified wood (primarily SiO2)