Sandstone Concretion
Ferruginous Sandstone Concretion
Category
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Sandstone Concretion
Ferruginous Sandstone Concretion
Picture Jasper
Silicon dioxide (SiO2)
Kambaba Jasper (Crocodile Jasper)
Stromatolitic Rhyolite/Jasper (SiO2)
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Quartz
Silicon Dioxide (SiO2)
Herkimer Diamond (Quartz)
Silicon Dioxide (SiO2)
Chert (Jasper and Chalcedony)
Silicon Dioxide (SiO2)
Black Jasper (Black Onyx substitute)
Silicon Dioxide (SiO2) with carbonaceous impurities
Red Chert
Microcrystalline Quartz (SiO2)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
Limonite (often after Hematite or Goethite)
Limonite (FeO(OH)·nH2O)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Jasper
Silicon Dioxide (SiO2)
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Jasper (Multi-color Chert)
Silicon dioxide (SiO2)
Blue Kyanite
Kyanite (Al2SiO5)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (CaCO3)
Quartz Mica Schist
Mica-Quartz Schist (Chemical: SiO2 + KAl2(AlSi3O10)(OH)2)
Glauconitic Sandstone (Greensand)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Jasper (specifically variegated or swamp jasper beads)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
Gneiss
Gneiss
Clear Quartz
Silicon Dioxide (SiO2)
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Oolitic Chert
Silicon Dioxide (SiO2) with Oolitic texture
Fossilized Turritella Gastropod (Internal Mold)
Turritella (Fossil Gastropod Crust)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Limestone
Calcium Carbonate (CaCO3)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Iron Oxide impurities)
Banded Agate (specifically Botswana Agate or Water-line Agate)
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Tree Agate
Dendritic Agate (Silicon Dioxide - SiO2)
Chalk (Sedimentary Limestone)
Calcium Carbonate (CaCO3) - Bioclastic Limestone
Pink Granite
Phaneritic intrusive igneous rock (Felsic)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Garnet (Almandine)
Almandine, Fe3Al2(SiO4)3
Fossiliferous Limestone
Biogenic Calcium Carbonate (CaCO3)
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Quartz veins)
Microcrystalline quartz (SiO2)
Chert
Chert (Microcrystalline Silica, SiO2)