Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Category
Browse organic specimen (fossil) specimens identified by the Rock Identifier community.
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Jasper (specifically Yellow Jasper and Red Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
Banded Chert (with Quartz Vein)
Microcrystalline Silica (SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Chert (Green variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
Jasper
Jasper (Silicon Dioxide, SiO2)
Red Amber (Burmite/Cherry Amber)
Succinite / Retinite (Organic Fossilized Resin, C10H16O)
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
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)
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 (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)
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)
Banded Chert
Microcrystalline Quartz (SiO2)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Jasper (likely Brown or Brecciated)
Jasper (Silicon Dioxide, SiO2)
Banded Chert
Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone
Sandstone (Clastic Sedimentary Rock)
Travertine (Tufa)
Calcium Carbonate (CaCO3)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)