Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Ironstone Concretion (Limonite/Hematite Nodules)
Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper variation)
Chert (SiO2)
Jasper
Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)
Orange Calcite
Calcium Carbonate (CaCO3)
Green Calcite
Calcium Carbonate (CaCO3)
Sandy Ironstone
Ferruginous Sandstone
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Glauconitic Sandstone
Glauconitic Quartz-Wacke / Sandstone (Fe(II),Fe(III),Al,Mg)2-3(Si,Al)4O10(OH)2
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Shale (possibly)
Shale (fine-grained clastic sedimentary rock)
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Baltic Amber
Succinite (Polmerized conifer resin)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
Chert (Nodular)
Chert (SiO2 - Microcrystalline Quartz)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Banded Chert (Jasper)
Silicon Dioxide (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Glauconitic Sandstone (or Greensand)
Glauconitic Siliciclastic Rock (Containing (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Jasper (likely Brown or Brecciated)
Jasper (Silicon Dioxide, SiO2)
Banded Chert
Cryptocrystalline Quartz (SiO2)
Gastropod Fossil (Internal Mold)
Phylum Mollusca, Class Gastropoda (Steinkern)
Shale
Shale (fine-grained clastic sedimentary rock)
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Slate
Slate (Foliated metamorphic rock)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Red Jasper (Plum or Brick variety)
Silicon Dioxide (SiO2) with iron oxide inclusions (Hematite)
Quartz Geode
Silicon Dioxide (SiO2)
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
Petrified Wood
Silicified wood (primarily SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)