Petrified Wood
Silicified Wood (SiO2)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2)
Coal (Bituminous or Anthracite)
Carbonaceous sedimentary rock (primarily Carbon, C)
Pearl
Organic Mineral (CaCO3 with conchiolin)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
Fossiliferous Limestone
Carbonate Rock (CaCO3 with organic inclusions)
Chert Concretion / Nodule
Microcrystalline Quartz (SiO2)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite organic gemstone
Ruby in Fuchsite
Corundum (Al2O3) in Chrome-Mica (K(Al,Cr)2(AlSi3O10)(OH)2)
Sodalite
Na8(Al6Si6O24)Cl2
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Azurite in Gossan
Azurite (Cu3(CO3)2(OH)2) in Limonite/Goethite matrix
Fossiliferous Limestone with Rugose Coral
Lithostrotionella (Limestone Matrix - CaCO3)
Manganese-coated Sandstone
Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)
Coarse Sand or Fine Gravel
Detrital Sedimentary Fragments (mostly SiO2)
Fossiliferous Kalkstein (Marl/Sandstone)
Fossiliferous calcarenite/siltstone
Arsenopyrite with Quartz
Arsenopyrite (FeAsS)
Shale
Shale (comprised mostly of clay minerals and quartz)
Shale
Fissile Mudstone (Shale)
Amber
Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
Glauconitic Sanstone (Glauconite)
Glauconite ((K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Fossiliferous Limestone (Shell Fragment)
Biogenic Limestone (Calcium Carbonate / CaCO3)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint/Jasper)
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Amber Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Chalcedony/Flint)
Silicon Dioxide (SiO2)
Shungite
Non-crystalline carbon (high-carbon metamorphic rock)
Pyrite
Iron Sulfide (FeS2)
Chert (Nodule)
Cryptocrystalline Quartz (SiO2)
Flint
Chert (Silicon dioxide, SiO2)
Chert (Arrowhead variety)
Chert (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Chalcedony
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)