so what are they used for?
Here is a copy/paste that explains what they were used for.
One of the most popular Mississippian artifacts today is the dislcoidal. What is a dislcoidal? The easiest answer is that a dislcoidal is a round Mississippian game stone that was used in the ancient Native American game known as chungkey or chunkey.
Discoidals, sometimes called discs, were treasured tribal possessions through the Mississippian world. They have been found across all of the great Mississippian lands including the states of eastern Oklahoma, Missouri, Arkansas, Illinois, Indiana, Tennessee, Kentucky, Alabama, Georgia, Louisiana and Mississippi. Although styles often very from region to region, they were all used as game stones. Discoidals began appearing at Late Woodland sites in eastern Missouri and southern Illinois around 700 A.D. By Mississippian times, chuckey's popularity had spread through the Mississippian world. Some Mississippian sites have produced more than one discoidal style, while others have produced only a single style.
Many surviving discoidals are both beautiful and durable. Quartz and granite were often used in the making of these popular game stones. Both materials are extremely hard, and they had to be. Discoidals were continually used in sporting contests over generations, so they had to be durable. A very few discoidals were made from colorful flint. Discoidals are very popular today with collectors because they come in many styles and colorful materials. Many are so finally made that today they are seen as works of sculptural art. The most frequently encountered discoidal styles are the Salt River, Jersey Bluff, Tennessee, Cahokia, Biscuit, Circle Roller, Apple, and Barrel.
