Out of a Carroll County, Indiana, collection, the flint has a very light "green" cast to it--Attica Chert--pretty standard field patina on one side, black mineral spotted on the reverse face. There are some slightly darker fossil inclusions all over the piece. Length is 2&7/8" by 1&5/8"--the width-to-thickness ratio is excellent, 5/16" (or barely over that, per caliper). The Cobbs Knife was in an early stage of use when lost, the bevel sharpening is thee (right side, not the left), but isn't so steep of a bevel--as a much longer used Cobbs would exhibit. The basal edge had a secondary use, you can see some 'rougher' edge flakes, but there is also work polish over those flakes--run an index finger across the chipped side and you'll feel the deliberate smoothing. They found a use for that edge, it'd seem. Every detail is lifetime guaranteed authentic, period. Shipping comes with the price, and I welcome checks or M.O>s. Sorry, I do not use paypal--Roy A.