Shungite
Shungite (carbon-rich Precambrian rock)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Shungite
Shungite (carbon-rich Precambrian rock)
Chert (specifically Tan Chert or Flint)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
Limestone
Calcium Carbonate (CaCO3)
Fossiliferous Limestone or Shale
Biomicrite (if limestone) or Fossiliferous Shale
Pyrite Concretion
Iron Sulfide (FeS2) in Sedimentary Matrix
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Chert (Jasper/Jasperoid)
Chert (chemically precipitated microcrystalline Quartz, SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Polished/Worn)
Microcrystalline quartz (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Weathered gray-green rock fragment
Likely shale or mudstone; exact identification requires testing
Gray River Pebble (likely Limestone or Siltstone)
Sedimentary Rock (Calcium Carbonate or Siliciclastic)
Tumbled amber
Fossilized plant resin; commonly succinite (C10H16O)
Moss Agate
Silicon Dioxide (Chalcedony with green mineral inclusions), SiO2
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
Chert with Quartz Veins
Microcrystalline Quartz (SiO2)
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Siltstone with Fossil Cast
Sedimentary Rock (Siltstone / Fine-grained Sandstone)
Pyrite in Shale
Iron Sulfide (FeS2) in Sedimentary Matrix
Shungite
Fullerene-bearing carbonaceous rock
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with hematite impurities
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Amber (Raw Copal)
Fossilized Plant Resin (Gummite/Succinite)
Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Chert (White Chert or Flint)
Microcrystalline Quartz (SiO2)
Red Sandstone
Arenite (Iron-rich Sandstone)
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
Chert Nodule / Flint
Microcrystalline Quartz (SiO2)
Chert (Field Stone)
Microcrystalline Quartz (SiO2)
Pyrite in Slate or Shale
Iron Sulfide (FeS2) in Argillaceous Matrix
Mookaite Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2)
Amazonite
Microcline Feldspar (KAlSi3O8)
Quartz
Silicon Dioxide (SiO2)
Lake Superior Agate
Banded Chalcedony (Silicon Dioxide / SiO2)
Quartz (Agate/Chalcedony variety)
Silicon Dioxide (SiO2)
Chalcedony Geode
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)