Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Category
Browse sedimentary (man made) specimens identified by the Rock Identifier community.
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Coquina
Coquina (Bioclastic Limestone)
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
Limestone
Sedimentary Rock (Primarily CaCO3)
Sandstone Pebble
Ferruginous Sandstone (SiO2 with Fe2O3)
Chert (Flint)
Silicon Dioxide (SiO2)
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Chert / Flint
Microcrystalline Quartz (SiO2)
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
Swirled Agate Bead
Silicon Dioxide (SiO2)
Flint / Chert
Microcrystalline quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Fossilized Shark Tooth
Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
Flint or chert, possibly a knapped stone tool
Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities
Chert (specifically White Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
Pyrite
Iron Sulfide (FeS2)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Chert (Black Chert or Flint)
Silicon Dioxide (SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Chert (often called Flint)
Chert (SiO2)
Sandstone
Sandstone (clastic sedimentary rock, predominantly SiO2)
Banded Gneiss
Gneiss (Foliated Metamorphic Rock)
Sandstone (likely Quartzose Sandstone)
Arenite
Chalk
Calcite (CaCO3)
Chert
Microcrystalline Quartz (SiO2)
Flint or chert fragment
Microcrystalline quartz (SiO₂), likely flint/chert
Red Sandstone
Arenite (Fe2O3 enriched)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Chert
Microcrystalline quartz (SiO2)
Chert (Yellow/Tan variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert Arrowhead
Microcrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert Nodule (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Weathered iron-rich rock, possibly jasper or ironstone
Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests
Red Sandstone
Quartz Arenite (iron-stained) / SiO2
Chert Nodule
Microcrystalline Quartz
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)