Rock Identifier

Category

Organic (Geological Interest)

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

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

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — metamorphic

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Chert with Limestone Cortex (Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)) — sedimentary

Chert with Limestone Cortex

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)

Mixed Gemstone and Mineral Collection (Silicon Dioxide (SiO2) based minerals and others) — mineral

Mixed Gemstone and Mineral Collection

Silicon Dioxide (SiO2) based minerals and others

Coral Fossil (Hexagonaria) (Hexagonaria sp. (Silica-replaced)) — fossil

Coral Fossil (Hexagonaria)

Hexagonaria sp. (Silica-replaced)

Tumbled amber-colored pebble (Likely quartz/chert or iron-stained chalcedony; exact identification requires testing) — mineral

Tumbled amber-colored pebble

Likely quartz/chert or iron-stained chalcedony; exact identification requires testing

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (often called Jasper or Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (often called Jasper or Flint)

Silicon Dioxide (SiO2)

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

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

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper (specifically a banded or dark variety) (Silicon Dioxide (SiO2) with impurities) — sedimentary

Jasper (specifically a banded or dark variety)

Silicon Dioxide (SiO2) with impurities

Moss Agate (Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions) — mineral

Moss Agate

Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions

Chert (often called Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Silicon Dioxide (SiO2)

Chert (specifically Flint or Gray Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint/Novaculite) (Chert (formula: SiO2)) — sedimentary

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Chert (often called Flint or River Rock) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or River Rock)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert / Flint (Chert (SiO2)) — sedimentary

Chert / Flint

Chert (SiO2)

Chert (Jasper/Flint Pebble) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Flint Pebble)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Moqui Marbles (Iron Oxide Concretion (Hematite/Goethite)) — sedimentary

Moqui Marbles

Iron Oxide Concretion (Hematite/Goethite)

Fossilized Coral (Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)) — sedimentary

Fossilized Coral

Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)

Fossiliferous Limestone (Biogenic Sedimentary Rock (CaCO3)) — sedimentary

Fossiliferous Limestone

Biogenic Sedimentary Rock (CaCO3)

Ironstone Concretion (Boxwork) (Siderite-Limonite Concretion (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Boxwork)

Siderite-Limonite Concretion (FeO(OH)·nH2O)

Limestone (with Chert) (Calcium Carbonate (CaCO3) / Microcrystalline Quartz (SiO2)) — sedimentary

Limestone (with Chert)

Calcium Carbonate (CaCO3) / Microcrystalline Quartz (SiO2)

Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression) (Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)) — sedimentary

Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression)

Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)

Amber (Copal) (Succiniferous Resin) — mineraloid

Amber (Copal)

Succiniferous Resin

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Banded Chert (likely Flint or Jasper variety) (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert (likely Flint or Jasper variety)

Silicon Dioxide (SiO2)

Green Chert (Jasper) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Green Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper

Microcrystalline Quartz (SiO2)

Chert / Flint (Silicon Dioxide (SiO2)) — sedimentary

Chert / Flint

Silicon Dioxide (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (Jasper/Chalcedony variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

Chert (White-Grey variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (White-Grey variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Yellow Jasper / Chert (Jasper (Silica/Quartz) - SiO2) — sedimentary

Yellow Jasper / Chert

Jasper (Silica/Quartz) - SiO2

Fossil Shell (Bivalve) (Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)) — sedimentary

Fossil Shell (Bivalve)

Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)

Chert (White Chert/Flint) (Chert (SiO2)) — sedimentary

Chert (White Chert/Flint)

Chert (SiO2)