Pyrite ps. Ammonite (Late Cretaceous)

Item Description

Fascinating and exceptional two-sided fossilized ammonite from South Dakota. One side of the very well-preserved and complete fossil is dramatically preferentially pyritized and polished. The striking, sculptural chambers are filled with sparkly microcrystalline pyrite. The beautiful, colorful and finely detailed reverse fossil shell is covered with opal-like iridescent ammolite (an organic gemstone) comprised primarily of Aragonite. This outstanding ammonite is Late Cretaceous age (101-66 MYA) and is of the Hoploscaphites genus.