Rock Identifier

Category

Organic (Geological Interest)

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

Fossiliferous Limestone (Fossiliferous Limestone (CaCO3 with organic inclusions)) — fossil

Fossiliferous Limestone

Fossiliferous Limestone (CaCO3 with organic inclusions)

Coral Fossil (Agatized Coral or Petoskey Stone) (Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)) — Sedimentary/Fossil

Coral Fossil (Agatized Coral or Petoskey Stone)

Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)

Sedimentary/Fossil

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Limestone Concretion (Botryoidal/Calcareous Nodules) (Calcium Carbonate Concretion (CaCO3)) — sedimentary

Limestone Concretion (Botryoidal/Calcareous Nodules)

Calcium Carbonate Concretion (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Jasper (Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)) — sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (and/or Flint) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Red Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Sandstone (Arenite (primarily composed of SiO2)) — sedimentary

Sandstone

Arenite (primarily composed of SiO2)

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

Chert (variant Flint)

Silicon Dioxide (SiO2)

Chert (specifically Yellow/Brown Chert or Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Yellow/Brown Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite-bearing Schist (Pyritic Quartz-Mica Schist with FeS2 inclusion) — metamorphic

Pyrite-bearing Schist

Pyritic Quartz-Mica Schist with FeS2 inclusion

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

Chert (Flint variety)

Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2

Chert (Jasper/Common Opal transition) (Microcrystalline Quartz (SiO2) with iron oxide inclusions) — sedimentary

Chert (Jasper/Common Opal transition)

Microcrystalline Quartz (SiO2) with iron oxide inclusions

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Paleoxylon (primarily SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Paleoxylon (primarily SiO2)

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

Chert / Flint

Chert (Silicon Dioxide, SiO2)

Chert (Jasper/Quartzite Pebble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Quartzite Pebble)

Silicon Dioxide (SiO2)

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

Glauconite sand

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

Cockle Shell (Fossil or Recent) (Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)) — Sedimentary (Biogenic, a type of fossil)

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Sedimentary (Biogenic, a type of fossil)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert Nodule / Ironstone Concretion (Microcrystalline Quartz (SiO2) with Iron Oxides) — sedimentary

Chert Nodule / Ironstone Concretion

Microcrystalline Quartz (SiO2) with Iron Oxides

Coquina Limestone (Fossiliferous Limestone) (Calcareous bioclastic sedimentary rock (CaCO3)) — sedimentary

Coquina Limestone (Fossiliferous Limestone)

Calcareous bioclastic sedimentary rock (CaCO3)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Brown Variety) (Silicon dioxide (SiO2)) — sedimentary

Chert (Brown Variety)

Silicon dioxide (SiO2)

Chert (and its variety Flint) (Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz) — sedimentary

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Coquina / Fossiliferous Limestone (Coquina (composed primarily of Calcium Carbonate / CaCO3)) — sedimentary

Coquina / Fossiliferous Limestone

Coquina (composed primarily of Calcium Carbonate / CaCO3)

Chert (often called Flint when dark) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint or Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Sandstone (Quartz-rich Arenite / SiO2)) — sedimentary

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Honey Calcite (Calcium Carbonate (CaCO3)) — mineral

Honey Calcite

Calcium Carbonate (CaCO3)

Ironstone Concretion (Ironstone (Siderite/Goethite/Hematite matrix)) — sedimentary

Ironstone Concretion

Ironstone (Siderite/Goethite/Hematite matrix)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement)) — fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement)