A decent piece of Hornstone, this Big Sandy, 2&3/8" by 1&3/16", only 5/16" max thickness. The colors of the flint, I wouldn't be surprised if some would call the flint "Sonora', not Hornstone. I see their point, a very close call as to which flint. The piece is out of a Vanderburgh Co., Indiana, collection, shows great Early Archaic knapping patterns (parallel flaking and pressure chipping, with some but not heavy, basal edge grinding. The way the 7500BP knapper worked the 'hooks' on the basal corner ends, that may have made it tough to grind the base with a piece of sandstone--he sure spent some time (care) on the four-sides sharpening, though, some of the best quadra-facial sharpening you'll come across. The patina is there, every detail guaranteed authentic. Shipping is $8.00, and only three methods of payment accepted: checks (or cash) and money orders. Sorry, I just don't use paypal-type services--Roy A.