I've looked at this Adena that came from a Tipton County, Indiana, collection time-and-again...still no closer to identifying the flint, but I'm pretty certain the flint is NOT the natural color of the flint, only heat treating brings out the iron oxides (reds) that color one flint to resemble something entirely different. I've been told Indiana Green flint (Attica Flint) turns purple under heat treating, SO--that's my 'guesstimate'--length is slightly over 2&3/4" by 1&1/4", the medial ridge reaching 7/16" in the hafting area--that thickness level would indicate a MUCH longer, larger (wider) blade prior to multiple sharpenings of the blade; the reverse side shows cortex. The piece is well made, a 'for,' that's nearing Adena Dixon in shape. The tip looks like it saw service as both a burin and a polishing feature--it shows some wear; guaranteed authentic, period. Shipping comes with the price, nothing additional. I take payments br check or money order, but do not use paypal-type services--Roy A.