Rock Identifier

Category

Organic (Geological Relative)

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

Petrified Wood (Siliconized Wood (SiO2)) — sedimentary

Petrified Wood

Siliconized Wood (SiO2)

Dendritic agate or included chalcedony (likely tumbled) (Microcrystalline quartz, SiO₂; inclusions likely manganese-oxide dendrites or iron minerals) — gemstone

Dendritic agate or included chalcedony (likely tumbled)

Microcrystalline quartz, SiO₂; inclusions likely manganese-oxide dendrites or iron minerals

Rounded basalt cobble (Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine) — igneous

Rounded basalt cobble

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Pumice (Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)) — Igneous

Pumice

Pumicite (Amorphous glass with varying chemical composition, often rhyolitic)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert Nodule in Limestone (Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert Nodule in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert (Chert (Silica: SiO2)) — sedimentary

Chert

Chert (Silica: 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)

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

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in sedimentary/volcanic host

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

Chert (Field Stone)

Silicon Dioxide (SiO2)

Red Jasper (Microcrystalline Quartz (Chalcedony), SiO2 with iron oxide inclusions) — sedimentary

Red Jasper

Microcrystalline Quartz (Chalcedony), SiO2 with iron oxide inclusions

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Chert (Red/Pink variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Red/Pink variety)

Microcrystalline quartz (SiO2)

Chert (Jasper) (Microcrystalline Quartz (SiO2) with Iron Oxide inclusions) — sedimentary

Chert (Jasper)

Microcrystalline Quartz (SiO2) with Iron Oxide inclusions

Fossiliferous Limestone (Coquina) (Biogenic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone (Coquina)

Biogenic Limestone (Calcium Carbonate, CaCO3)

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

Chert (Jasper/Flint variant)

Microcrystalline Quartz (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Chert (often called Flint in this variation) (Silicon dioxide (SiO2) - Microcrystalline quartz) — sedimentary

Chert (often called Flint in this variation)

Silicon dioxide (SiO2) - Microcrystalline quartz

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (variations include Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

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

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

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

Chert (often called Jasper or Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite in Shaly Matrix (Iron Sulfide (FeS2)) — mineral

Pyrite in Shaly Matrix

Iron Sulfide (FeS2)

Greenstone pebble, likely serpentine or altered basalt (Probably serpentinite (serpentine-group minerals, Mg₃Si₂O₅(OH)₄) or chlorite-rich greenschist) — metamorphic

Greenstone pebble, likely serpentine or altered basalt

Probably serpentinite (serpentine-group minerals, Mg₃Si₂O₅(OH)₄) or chlorite-rich greenschist

Likely chalcopyrite-bearing sulfide ore (Chalcopyrite (CuFeS₂), possibly with pyrite and secondary copper minerals) — mineral

Likely chalcopyrite-bearing sulfide ore

Chalcopyrite (CuFeS₂), possibly with pyrite and secondary copper minerals

Chert (Brown Variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Brown Variety)

Microcrystalline quartz (SiO2)

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

Granite / Feldspar gravel

Granite (felsic intrusive igneous rock)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert / Chalcedony (Agatized) (Silicon dioxide (SiO2)) — sedimentary

Chert / Chalcedony (Agatized)

Silicon dioxide (SiO2)

Chert (Limestone-based) (Silicon dioxide (SiO2)) — sedimentary

Chert (Limestone-based)

Silicon dioxide (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Jasper (Silicon Dioxide (Microcrystalline Quartz, SiO2)) — sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Jasper (Silicon Dioxide (Microcrystalline Quartz, SiO2)) — sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

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

Chert (variant Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chrysanthemum Stone (Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix) — metamorphic

Chrysanthemum Stone

Celestine (SrSO4) or Calcite (CaCO3) in Limestone/Porphyry matrix

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

Chert / Jasper

Microcrystalline Quartz (SiO2)

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

Chert (Jasper variety)

Cryptocrystalline Quartz (SiO2)

Chert (with Limestone matrix) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (with Limestone matrix)

Microcrystalline Quartz (SiO2)