Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
Bivalve Shell (Fossil or Contemporary)
Class Bivalvie (various genera and species of clams, cockles, etc.)
Pyrite
Pyrite (Iron Disulfide), FeS2
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (C10H16O)
Baltic Amber (Butterscotch variety)
Succinite
Shale
Shale (clastic sedimentary rock)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Ambergris
Ambra grisea (Metabolic byproduct)
Ambergris
Ambrein-rich Calculus
Pyrite
Pyrite (Iron sulfide, FeS₂)
Brachiopod Fossil (Spiriferid)
Phylum Brachiopoda, Order Spiriferida (CaCO3 - Calcium Carbonate)
Brachiopod Fossil (Spiriferid)
Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)
Flint (chert), likely brown flint
Microcrystalline quartz/chalcedony (SiO₂)
Chert (variously identified as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tumbled amber
Amber (fossilized plant resin), chiefly polymerized diterpenoid resin
Chert / Jasper Pebble
Microcrystalline Quartz (SiO2)
Pumice
Vesicular volcanic glass (primarily SiO2 with Al2O3)
Staghorn Coral Specimen
Acropora cervicornis (Calcium Carbonate, CaCO3)
Limestone with Lichen/Algae
Sedimentary Calcium Carbonate (CaCO3)
Fossiliferous Flint or Chert with Bryozoan Fossils
Sedimentary cryptocrystalline quartz (SiO2) with fossil inclusions
Aragonite Star Cluster
Aragonite (CaCO3)
Chert / Fossiliferous Limestone
Sedimentary Chert (often containing CaCO3 or SiO2 replacements)
Fossiliferous Limestone
Calcium carbonate (CaCO3) with marine fossils
Coral Fossil
Anthozoa (order Scleractinia)
Chert (Flint Nodular)
Silicon Dioxide (SiO2)
Fossilized Coral (Petoskey Stone / Favosites)
Favosites (extinct genus of tabulate coral)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
Limestone (Cliff Formation)
Limestone (predominantly CaCO3 as calcite)
Fossiliferous Limestone
Biogenic Calcium Carbonate (CaCO3)
Banded Sandstone (Hag Stone)
Arenite Sandstone (SiO2 with impurities)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Bivalve Fossil (Shell-bearing Sedimentary Rock)
Class Bivalvia (Phylum Mollusca) within a Calcarenite/Sandstone matrix
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclastic Inclusions
Fossiliferous Chert or Limestone
Sedimentary rock containing fossilized marine invertebrates (likely crinoid stems or bryozoans)
Aragonite
Aragonite (CaCO3)
Fossil Sand Dollar (Echinoidea)
Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)