Weathered limestone
Calcitic limestone, mainly calcium carbonate (CaCO₃)
sedimentary
Category
Sedimentary (Biogenic Sediment Or Biological Remain)
Browse sedimentary (biogenic sediment or biological remain) specimens identified by the Rock Identifier community.
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Septarian Nodule
Septarian Concretion (Calcite, Aragonite, and Limestone)
sedimentary
Ironstone Concretion
Ferruginous Sandstone / Siderite Concretion
sedimentary
Sandstone Concretion
Septarian or Carbonate-cemented Sandstone Concretion
sedimentary
Sandstone Concretion
Clastic Sedimentary Rock (primarily SiO2 with mineral cement)
sedimentary
Ironstone Concretion
Limonitic/Hematitic Concretion
sedimentary
Sandstone Geode (Ironstone Concretion)
Arenite with Limonite/Hematite matrix (SiO2 with Fe-oxides)
sedimentary
Rounded river pebble
Indeterminate; likely quartz-rich sandstone, chert, or weathered volcanic rock
sedimentary
River Pebbles (Chert and Quartzite)
Sedimentary Clastic Rock (Silica-rich)
sedimentary
Banded Chert (River Siltstone)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Banded)
Microcrystalline Quartz (SiO2)
sedimentary
Greywacke
Lithic Sandstone (Greywacke - (SiO2+Al2O3+Fe2O3))
sedimentary
Ammonite Fossil
Ammonoidea (subclass)
fossil
Fossil Shark Tooth
Elasmobranchii (Lamniformes order likely)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Sandstone Concretion
Septarian Concretion (Nodule)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Chert (Flint / Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper/Flint)
Silicon dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Fossilized oyster or bivalve shell
Fossil Gryphaeidae or Ostreoidea; calcitic shell, CaCO₃
fossil
Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Jasper
Silicon dioxide (SiO2) with iron oxide impurities
sedimentary
Shungite
Non-crystalline carbon (high-carbon metamorphic rock)
metamorphic
Ferruginous Sandstone (with Pyrite/Gold associations)
Ferruginous Arenite (SiO2 + Fe2O3)
sedimentary
Sand Grain (Silica/Quartz Grain)
Silicon Dioxide (SiO2)
sedimentary
Concretion in Shale
Siltstone/Shale with Siderite or Calcareous concretions
sedimentary
Petrified Wood
Silicified Wood (SiO2)
fossil
Petrified Wood
Silicified Wood (mainly Quartz / SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossiliferous Limestone
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossilized Shark Tooth
Chondrichthyes (class) fossilized tooth
fossil
Fossilized Bone
Fossilized Vertebrate Bone (Per mineralized)
fossil
Sandstone with Trace Fossils
Arenite / Quartzwacke with Ichnofossils
sedimentary
Tumbled brown pebble
Indeterminate; likely quartz-rich sandstone or chert
sedimentary
Water-worn brown chert or jasper pebble
Microcrystalline quartz (SiO₂), likely ferruginous chert/jasper
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (goethite)
sedimentary
Septarian Nodule
Septarian Concretion (CaCO3 + Hydrated SiO2)
sedimentary
Sandstone (Banded)
Arenite (primarily SiO2)
sedimentary
Greywacke
Lithic Sandstone (Greywacke)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - variety Jasper
sedimentary