Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
Amber
Succinite (specific to Baltic amber), fossilized tree resin
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Bituminous Coal
Bituminous coal (Organic Sedimentary Rock)
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Chert Pebble with Quartz Veins
Microcrystalline Quartz (SiO2)
Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
Coal (Bituminous or Anthracite)
Carbonaceous sedimentary rock (primarily Carbon, C)
Nephrite Jade
Nephrite
Dyed Pink Quartzite (Jadeite Simulant)
Silicon Dioxide (SiO2) with organic dye
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
Chert (containing Flint and Calcareous inclusions)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities
Amber
Succinite
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Chert (specifically Jasper/Brown Chert)
Silicon Dioxide (SiO2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Black Jasper (Black Onyx substitute)
Silicon Dioxide (SiO2) with carbonaceous impurities
Chert (Smooth River Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Nodular)
Chert (SiO2 - Microcrystalline Quartz)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Chert (and/or Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Transit Token (RTD Denver)
Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)
Yellow Chert
Sedimentary cryptocrystalline quartz (SiO2)
Fossil Shell Fragment (possibly Brachiopod or Bivalve)
Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca
Shale
Shale (fine-grained clastic sedimentary rock)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Graphite
Graphite (Carbon, C)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Druzy Quartz on Vesicular Basalt
Silicon Dioxide (SiO2) in an extrusive Mafic igneous host rock
Fossilized Gastropod (Snail)
Class Gastropoda (internal mold or 'steinkern')
Chert (specifically Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (and Flint)
Cryptocrystalline Quartz (SiO2)
Glauconitic Sandstone
Glauconitic arenite (contains (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Chert (Flint)
Silicon Dioxide (SiO2)