Chert (specifically Flint or Common Chert)
Silicon Dioxide (SiO2)
Category
Browse organic (geological interest) specimens identified by the Rock Identifier community.
Chert (specifically Flint or Common Chert)
Silicon Dioxide (SiO2)
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
Chert Nodules in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Jasper
Silicon dioxide, SiO2
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (containing Flint and Calcareous inclusions)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities
Fossil Coral (Rugosa or Solitary Coral)
Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)
Petrified Wood
Silicified Wood (SiO2)
Anthracite Coal
Carbon (with trace impurities)
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Pitted Limestone
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (primarily Silicon Dioxide, SiO2)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Petrified Wood
Silicified wood (primarily SiO2)
Fossiliferous Limestone (with Crinoids)
CaCO3 (Calcium Carbonate)
Flint / Chert Nodule
Microcrystalline quartz (SiO2)
Petrified Wood / Jasper Chert
Silicified Wood / Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Moqui Marble (Shaman Stone)
Ironstone Concretion (Goethite/Hematite Shell)
Petrified Wood
Silicified Wood (SiO2)
Pyrite Concretion
Iron Sulfide (FeS2) in Sedimentary Matrix
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Agatized Petrified Wood
Silicon Dioxide (SiO2) - Chalcedony pseudomorph after Wood
Fossiliferous Limestone with Brachiopod shell
Calcium carbonate (CaCO3)
Gastropod Fossil (Snail Steinkern)
Class Gastropoda (internal mold)
Petrified Wood
Silicified Wood (SiO2)
Shale
Mudrock / Fissile Shale
Chert (likely brown flint)
Microcrystalline quartz, SiO₂ (chalcedonic quartz aggregate)
Limestone
Calcareous sedimentary rock (CaCO3)
Chert (Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (and Jasper blend)
Chert (Microcrystalline Quartz, SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Glauconitic Sandstone (Greensand pebble)
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)