Rock Identifier

Category

Organic (Geological Interest)

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

Quartz Geode (Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host) — mineral

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host

Siltstone with Fossil Cast (Sedimentary Rock (Siltstone / Fine-grained Sandstone)) — sedimentary

Siltstone with Fossil Cast

Sedimentary Rock (Siltstone / Fine-grained Sandstone)

Fossil Coral (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Pyrite-bearing rock (likely pyrite in a quartz or sulfide-rich matrix) (Pyrite, FeS₂; the gray host may be quartz, carbonate, or another sulfide-bearing rock) — mineral

Pyrite-bearing rock (likely pyrite in a quartz or sulfide-rich matrix)

Pyrite, FeS₂; the gray host may be quartz, carbonate, or another sulfide-bearing rock

Sea Shell (Mollusk Shell) (Calcium Carbonate (Aragonite/Calcite)) — fossil

Sea Shell (Mollusk Shell)

Calcium Carbonate (Aragonite/Calcite)

Seashell Fossil (Gastropoda fossil) — fossil

Seashell Fossil

Gastropoda fossil

Glauconite (Greensand Articulated Sandstone) (Glauconite ((K, Na)(Fe, Al, Mg)2(Si, Al)4O10(OH)2)) — sedimentary

Glauconite (Greensand Articulated Sandstone)

Glauconite ((K, Na)(Fe, Al, Mg)2(Si, Al)4O10(OH)2)

Seashell (Cone Snail Shell) (Conus sp. (Calcium Carbonate, CaCO3)) — fossil

Seashell (Cone Snail Shell)

Conus sp. (Calcium Carbonate, CaCO3)

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

Glauconite (Greensand)

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

Manganese Dendrite on Siltstone (Manganese Oxide (pyrolusite or psilomelane) Dendrites) — mineral/sedimentary

Manganese Dendrite on Siltstone

Manganese Oxide (pyrolusite or psilomelane) Dendrites

mineral/sedimentary

Coral Fossil (Scleractinia) (Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)) — sedimentary

Coral Fossil (Scleractinia)

Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)

Chert (Yellow Jasper variant) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (CaCO3 (principally Calcite or Aragonite)) — sedimentary

Fossiliferous Limestone

CaCO3 (principally Calcite or Aragonite)

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

Chert (specifically Jasper/Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (and Jasper/Chalcedony variety)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone / Fossil Fragment (Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)) — fossil

Fossiliferous Limestone / Fossil Fragment

Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)

Tufa Rock and Tumbled Gemstones (Calcareous Tufa (Calcium Carbonate, CaCO3)) — sedimentary

Tufa Rock and Tumbled Gemstones

Calcareous Tufa (Calcium Carbonate, CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Fossil Bivalve / Ostreid Shell (Hag Stone / Perforated Pebble) (Phylum Mollusca, Class Bivalvia) — fossil

Fossil Bivalve / Ostreid Shell (Hag Stone / Perforated Pebble)

Phylum Mollusca, Class Bivalvia

Granite / Feldspar gravel (Granite (felsic intrusive igneous rock)) — igneous

Granite / Feldspar gravel

Granite (felsic intrusive igneous rock)

Petrified Wood (Siliconized Wood (SiO2)) — sedimentary

Petrified Wood

Siliconized Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Green Jasper (Microcrystalline Quartz (Chalcedony), SiO2) — sedimentary

Green Jasper

Microcrystalline Quartz (Chalcedony), SiO2

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

Chert / Flint

Silicon Dioxide (SiO2)

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

Chert / Flint

Microcrystalline Quartz (SiO2)

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

Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Pearl (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

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

Chert (Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Chert Nodules in Limestone (Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert Nodules in Limestone

Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Flint with Fossil Inclusion (Cryptocrystalline quartz (SiO2) enclosing fossilized organic remains) — sedimentary

Flint with Fossil Inclusion

Cryptocrystalline quartz (SiO2) enclosing fossilized organic remains

Chert (specifically a fragment with Desert Varnish) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (specifically a fragment with Desert Varnish)

Microcrystalline quartz (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Limestone (Calcium carbonate (CaCO3)) — sedimentary

Limestone

Calcium carbonate (CaCO3)

Petrified Wood / Red Jasper (Silicified wood (primarily Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood / Red Jasper

Silicified wood (primarily Silicon Dioxide, SiO2)