Plows did a number on this Monticello, Kentucky, area field find--maybe not as much as soil conditions did, though--only on a few pieces have I ever seen patina so radically different--what caused it I can't even guess. Too, what I assume is plow damage could also be a "find-and-use" by a later culture than the peoples who made the knife--it happened to a lot of artifacts, sort of like finding a tool on the side of a road..."I can use that". So, is this 3&13/16" by 1&5/8" thin (3/8") knife Sonora Flint, Kentucky Blue Flint, or is it Hornstone with coloration all due to soil conditions--honestly, take your pick, I think you could make a case for any of the listed flint types. Culture--i.e. who made the knife? Flint 'flake scars' that cross the medial ridge, only one ancient culture used outre pas (over shot) flaking: Paleo hunters, Clovis and some of the other Late Paleo groups; study their work, it's easily recognized. While all the more recent damage/ rework is there, it's also an artifact you'll find a neat fit for your collection, a real "conversation piece". Shipping is $8.00, checks, cash, or M.O.s are how I welcome-in payments. Sorry, I do not use paypal-type services--Roy A.