Was this a Celt (of Burlington Chert), a Spade/ or hoe, or just a big 3&15/16" by 2&1/8", nearly 1" thick Knife...the answer may be (in large part) on what we think it was used for. On the very thickest high spot I find use polish--but don't see bit polish on either end (as a spade would show) why? Around the circumference, somewhere or other you'd expect a dulled spot, somewhere where a fingertip could exert downward pressure for cutting--no single spot stands out as a 'grip spot', so was the piece hafted, not hand-held? Obvious use & age patina are there, that polish of the highest portion of the medial ridge was no accident, so how'd they use/ hold the blade--no answers. Out of the Decatur, Illinois, area, 100% guaranteed authentic in every detail, that's what I can provide (as to provenance)--it's real. Shipping is $10--what USPS will charge for a small box. I welcome checks, cash, or M.O.s but do not use paypal-type services--Roy A.