Anthracite Coal
Carbon (with trace impurities)
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Anthracite Coal
Carbon (with trace impurities)
Limestone
Calcium carbonate (CaCO3) / Limestone
Sandstone
Sandstone (SiO2-dominated clastic rock)
Limestone
Calcium Carbonate (CaCO3)
Chert (Flint Nodules)
Silicon dioxide (SiO2)
Chert (Field Stone)
Microcrystalline Quartz (SiO2)
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert Nodule in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Fossil Coral
Cnidaria Anthozoa (Fossilized)
Fossilized Gastropod / Coral
Phylum Mollusca / Cnidaria (Silicified or Calcified)
Amber
Succinates (Fossilized Tree Resin)
Moss Agate
Silicon dioxide (SiO2) with inclusions
Chert (Flint)
Microcrystalline Quartz (SiO2)
Shungite
Carbon-rich mineraloid (Amorphous carbon)
Grey Limestone
Calcium Carbonate (CaCO3)
Limestone (with weathering rind)
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Chert (Jasper-rich)
Silicon Dioxide (SiO2)
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone with Brachiopod shell
Calcium carbonate (CaCO3)
Chert (Green Chert)
Microcrystalline silica (SiO2)
Coal
Anthracite / Bituminous Coal
Fossilized Shark Tooth
Elasmobranchii gen. sp. indet. (Calcium Phosphate - Ca5(PO4)3(OH,F,Cl))
Chert Concretion
Sedimentary Cryptocrystalline Quartz (SiO2)
Fossilized Brachiopod
Brachiopoda (Phylum)
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcedony replacement)
Chert (Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Field Stone)
Chert (Silicon Dioxide, SiO2)
Chert (and Chalcedony)
Microcrystalline Quartz (SiO2)
Shale with Iron Staining
Fissile Mudrock (Sedimentary Rock)
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)