Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
Chert (River Pebble)
Cryptocrystalline Quartz (SiO2)
Ironstone Concretion / Hematite Nodules
Ferruginous Sedimentary Rock (primarily Hematite Fe2O3 and Goethite FeO(OH))
Limestone
Sedimentary Rock (Primarily Calcium Carbonate, CaCO3)
Chert (containing Flint and Calcareous inclusions)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities
Chert (Commonly called Jasper or Flint)
Chert (SiO2)
Amber
Succinates
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Limestone with Fossil Inclusions
Sedimentary Carbonate Rock (CaCO3)
Fossil Shark Tooth
Carcharodon sp. (likely Otodus or similar Lamniformes order)
Asphalt / Bituminous Aggregate
Bituminous mixture (Hydrocarbon-based sediment)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (chemical formula: C10H16O)
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
Carved red coral bead (likely coral or coral-colored resin)
Corallium spp. (precious coral; calcium carbonate, CaCO₃)
Blue-gray limestone or marble fragment
Calcite-rich carbonate rock; likely calcitic marble (CaCO₃), though limestone is possible
Chert (Flint)
Chert (Cryptocrystalline Silicon Dioxide, SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Limestone
Calcareous sedimentary rock (CaCO3)
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
Chert (Flint)
Chert (̑SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Pebble)
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Banded Chert with Quartz Veining
Microcrystalline Quartz (SiO2)
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
Amber
Succinate (Fossilized Resin)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Crushed Limestone
Sedimentary Calcium Carbonate (CaCO3)
Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Limestone (or Calcite Nodules)
Calcium Carbonate (CaCO3)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Fossiliferous limestone (likely ammonite/gastropod-bearing)
Bioclastic limestone; predominantly calcite (CaCO₃)
Limestone
Calcium carbonate (CaCO3) / Limestone
Red Jasper
Microcrystalline Quartz (Chalcedony), SiO2
Chert with Calcite Veining
Microcrystalline Quartz (SiO2) with Calcium Carbonate (CaCO3) veins
Smurf Rock (Fictional Interpretation)
Cyanus Anthropomorphicus (Geologic Simulation)
Lignite (Brown Coal)
Humic Lignite (Carbonaceous sedimentary rock)