Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Smurf Rock (Fictional Interpretation)
Cyanus Anthropomorphicus (Geologic Simulation)
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Chert Pebble
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Yellow Chert
Sedimentary cryptocrystalline quartz (SiO2)
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Graphite Schist
C (Carbonaceous Schist)
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert / River Pebble
Silicon Dioxide (SiO2)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Schist
N/A (a rock type, not a mineral formula)
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
Serpentine
Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)
Chert (Nodule)
Silicon Dioxide (SiO2)
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Amber
Succinicum (C10H16O)
Chert (Holey Stone)
Microcrystalline Quartz (SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
Glauconitic Sandstone
Glauconitic arenite (contains (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Petrified Wood
Silicified Wood (SiO2)
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Flower Jasper
Agatized Fossil Coral / Chalcedony (SiO2)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Chert (Jasper)
Silicon dioxide (SiO2)