Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
Category
Browse sedimentary (fossil) specimens identified by the Rock Identifier community.
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
Sandstone (Calcareous)
Clastic sedimentary rock (primarily SiO2 with CaCO3 cement)
Limestone with Calcareous Accretion
Sedimentary Carbonate Rock (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 principal component)
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
Limestone
Calcium Carbonate (CaCO3)
Crinoid Fossil Fragment
Crinoid stem fossil (Echinodermata)
Calcite-rich limestone, possibly fossiliferous
Limestone composed mainly of calcite (CaCO₃), potentially containing a fragmentary fossil or calcite-filled structure
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Sandstone Pebbles
Arenite (Sedimentary rock composed of sand-sized grains)
Crushed Limestone
Calcium Carbonate (CaCO3)
Chert (v. Flint)
Sedimentary Cryptocrystalline Quartz (SiO2)
Quartz Geode in Sedimentary Matrix
Silicon Dioxide (SiO2) within a limestone/dolostone host
Flint or chert fragment
Microcrystalline quartz (SiO₂), likely flint/chert
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Kambaba Jasper
Stromatolite (Fossilized Algae within Microcrystalline Quartz)
Petrified Wood
Silicon Dioxide (SiO2) permineralized organic matter
Fossilized Rugose Coral (Horn Coral)
Rugosa (Order) - often Grewingkia or Zaphrenthis
Petrified Wood
Silicified Wood (SiO2)
Fossiliferous Limestone
Calcite (CaCO3) Rich Bio-sedimentary Rock
Hag Stone
Perforated Flint or Chert
Shale
Fissile Mudstone
Sandstone with trace fossil
Sandstone, possibly with Skolithos or similar trace fossil
Shale (with Iron Oxide staining)
Fissile Mudstone (primarily Quartz and Clay minerals)
Weathered limestone pebble
Limestone, primarily calcite (CaCO₃)
Fossiliferous Limestone
Calcite (CaCO3) with Bioclastic inclusions
Red Sandstone
Ferruginous Sandstone (formula varies, primarily SiO2 with Fe2O3)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone (Red Sandstone)
Arenite (SiO2 based with Fe2O3 staining)
Limestone Boulder
Sedimentary Rock (Calcium Carbonate, CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Fossil Shell (Bivalve)
Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)
Sandstone
Arenite (SiO2 dominant)