Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limestone with Lichen
Carbonate Sedimentary Rock (primarily CaCO3)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Chert (River Stone)
Microcrystalline Quartz (SiO2)
Shark Tooth Fossil
Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)
Sandstone
Arenite (primarily composed of SiO2)
Chert (Siliceous Mudstone variant)
Microcrystalline quartz (SiO2)
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
Red Coral
Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Carbonate Sedimentary Rock (primarily CaCO3)
Moss Agate (Crescent Moon Shape)
Silicon Dioxide (SiO2) with iron/manganese inclusions
Fossiliferous Limestone
Biogenic Limestone (CaCO3)
Chert (Flint) with Limestone Matrix
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
Weathered River Rock (likely Chert or Basalt with algae)
Silicon dioxide (SiO2) with organic biofilm
Chert (Jasper)
Silicon dioxide (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Black Marble
Recrystallized Limestone (CaCO3)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Fossiliferous Sandstone / Fossil Fragment
Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material
Dendritic Agate (Tree Agate)
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Travertine (Tufa)
Chemical Sedimentary Rock (CaCO3)
Chert (often called Jasper or River Siltstone)
Chert (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
Chert Pebble
Microcrystalline Quartz (SiO2)
Chert Nodules (Jasper)
Microcrystalline Quartz (SiO2)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)