This fossil is a member of the Species Hoploscaphites Nicoletti which is from the Cretaceous Period some 60 million years ago. It is from the Fox Hills Formation in South Dakota.
This is a very nice find of a high quality Schafite in matrix from South Dakota. The Schafite has a natural, iridescent, pearl-like finish. The larger Schafite measures 2 5/8″ x almost 2 1/2″ x nearly 3/4″ in a fossilized limestone matrix measuring 4 5/8″ x 4 5/8″ x 5 1/8″ tall and weighs nearly 3 3/4 pounds. Close observation will reveal many other partial to semi-complete fossils throughout the matrix. These fossils make great gifts or work wonderful as an educational tool for school, scouts or clubs.