If the (relatively) huge flake scars don't immediately tell you this is a Clovis Knife then I'd be surprised. Only one culture did the "Overshot" (Outre Pas) flaking: Paleo knappers. Note that the circumference is all knapped with small pressure chipping--the "finish out" knapping. Out of a Martin County--Lawrence County, Indiana, based collection, the flint is Indiana Stanford Chert--same chert family as Indiana Derby and Holland-Spencer County Chert. Length is 3&13/16" by 2&7/16"--what makes the piece somewhat translucent (other than the Chalcedony-like flint) is the thinness--only a max 3/8", but generally 5/16" thickness--light passes through the blade as the back-lighted photo shows. I can't say for certain the piece was a creek find, but some of the iron bearing soil still in the crevices will not wash off: it's embedded--and I'm not planning on scrubbing a Paleo artifact, removing natural patina. EVERY detail is guaranteed authentic, period. Shipping is $10 as the piece will be super-well packed. I welcome checks or M.O.s, but do not use paypal-type services--Roy A.