Chert / Chalcedony
Silicon Dioxide (SiO2)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Chert / Chalcedony
Silicon Dioxide (SiO2)
Chert (and Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert Nodules in Limestone
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
River Cobble (Sandstone)
Arenite (primarily SiO2)
Dark gray flint or chert fragment
Microcrystalline quartz (SiO₂), commonly with minor chalcedony and impurities
Red Jasper with Quartz
Microcrystalline Quartz (SiO2)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone
Sandstone (SiO2-dominated clastic rock)
Pearl necklace
Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)
Limestone
Calcareous sedimentary rock (CaCO3)
Jasper
Microcrystalline Quartz (SiO2)
Shale or Slate
Shale (Sedimentary) or Slate (Metamorphic)
Chert (Common Opal or Agate)
Microcrystalline Quartz (SiO2)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Fossilized Shark Tooth
Chondrichthyes (Class)
Poppy Jasper
Microcrystalline Quartz (SiO2) with mineral inclusions
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Chert (Flint)
Chert (SiO2)
Bivalve seashell
Calcareous shell, primarily aragonite (CaCO₃); likely a modern cockle or related bivalve
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Travertine
Travertine (a terrestrial form of Limestone, CaCO3)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Chert (Cryptocrystalline Silica, SiO2)
Chert (Field Stone)
Silicon Dioxide (SiO2)
Shale
Shale (Fine-grained clastic sedimentary rock)
Petrified Wood
Silicon Dioxide (SiO2)
Smurf Rock (Fictional Interpretation)
Cyanus Anthropomorphicus (Geologic Simulation)
Petrified Wood
Silicified wood (SiO2)
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
Chert (Jasper-rich)
Silicon Dioxide (SiO2)
Tahitian black pearl strand
Cultured pearl; aragonite (CaCO₃) nacre
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (̑SiO2)
Chert (Black Flint)
Silicon Dioxide (SiO2)
Chert (Pebble)
Chert (Microcrystalline Quartz, SiO2)
Chert (Nodule)
Microcrystalline quartz (SiO2)
Fossilized Shell
Invertebrate fossil (Bivalvia or Brachiopoda)