Patina, mineralization all over the surface of this Copena Knife, and enough limestone adhering to the Woodland Culture blade that you wonder if it spent time in a rockshelter. The last owner lived in Illinois, but he added enough Kentucky points to his collection to keep you guessing "Where'd he get this one?"...far easier when you see this much mineral build-up, you know only rock shelter or creek finds patinate this way. The 2&13/16" hornstone blade is either a Kentucky or possibly Tennessee-type Hornstone, it doesn't have the color of an Illinois hornstone (Cobden), although there are always exceptions. The culture (Copena) and the knapping style are clearly Woodland Culture, percussion work, so that's how I'm evaluating the piece--authenticity is no brainer, I think anyone will agree simply by looking at the pictures. Shipping is $8.00 (to keep up with USPS zone charges), and I welcome payment by check, cash, or M.O.. Sorry, I do not use paypal-type payment services--Roy A.