Rock Identifier

Category

Organic Gemstone (Sedimentary Classification)

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

Fossiliferous Limestone (Coral Fossil) (Scleractinian Coral in Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (Coral Fossil)

Scleractinian Coral in Calcium Carbonate (CaCO3)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Anthracite Coal (Anthracite (Carbon-rich metamorphic coal)) — metamorphic

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Fossilized Horn Coral (Order Rugosa (Rugose Coral)) — sedimentary

Fossilized Horn Coral

Order Rugosa (Rugose Coral)

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

Coral Rock (Coquina)

Biogenic Limestone (Calcium Carbonate - CaCO3)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Sandstone Chert Concretion (Silica-cemented Concretion (primarily SiO2)) — sedimentary

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Chert (specifically Gray Chert) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Gray Chert)

Silicon Dioxide (SiO2)

Chert / Flint (with Crinoid Stem Molds) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Flint (with Crinoid Stem Molds)

Microcrystalline Quartz (SiO2)

Dinosaur Fossil (Skull) (Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)) — sedimentary

Dinosaur Fossil (Skull)

Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Lignite (Brown Coal) (Humic Lignite (Carbonaceous sedimentary rock)) — sedimentary

Lignite (Brown Coal)

Humic Lignite (Carbonaceous sedimentary rock)

Petrified Wood (Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)

Chert / River Pebble (Silicon Dioxide (SiO2)) — sedimentary

Chert / River Pebble

Silicon Dioxide (SiO2)

Glauconitic Sandstone (Greensand) (Glauconitic quartz wacke or arenite) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic quartz wacke or arenite

Chert (variously identified as Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (variously identified as Flint)

Microcrystalline Quartz (SiO2)

Gray Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Gray Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert (often called Flint or Jasper when red) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (often called Flint or Jasper when red)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

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

Chert (Nodule)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Moqui Marbles

Iron Oxide Concretion (Hematite/Goethite)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Field Stone) (Chert (SiO2)) — sedimentary

Chert (Field Stone)

Chert (SiO2)

Chert (Pink Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Pink Jasper)

Microcrystalline Quartz (SiO2)

Chert (Tan/Brown) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (Tan/Brown)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

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

Chert (Iron-stained variant)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint)

Microcrystalline Quartz (SiO2)

Black Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Black Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (v. Flint) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (v. Flint)

Sedimentary Cryptocrystalline Quartz (SiO2)

Chert (Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (Pebble)

Microcrystalline silica (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Jasper/Quartzite variety) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Jasper/Quartzite variety)

Microcrystalline Silica (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

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

Chert (Nodular Chert)

Silicon Dioxide (SiO2)

Chert (Chert Nodule with Cortex) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert Nodule with Cortex)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Jasper or Flint)

Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Chert (specifically Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint)

Cryptocrystalline Quartz (SiO2)