Description

Septarian, also known as a type of Concretion, is a volume of sedimentary rock in which a mineral cement fills the porosity.  Concretions are often ovoid or spherical in shape.  They form within layers of sedimentary strata that has already been deposited.  It is composed of a Carbonate mineral such as Calcite, a Silica such as Chert, Flint or Jasper or an Iron Oxide such as Goethite or Hematite.  It is commonly found in Shale, Siltstones and Sandstones.