Numerous inclusions all over the surface of the normally whitish-grey Mill Creek Chert, it gives the flint a more Kaolin-like look--the flints may be more alike from a geologist's point of view that we collectors assume. Here, I'm guessing the iron content made the chert much harder--definitely made the Union--Jackson County, Illinois Mississippian spade more colorful. Length is 6&13/16" by 2&15/15", thickness never exceeds 13/16", and that's only on a small 'stack' in the center--most of the spade is in the 5/8" thickness range. The bit shows some absolutely great polish from all that corn chopping in sandy rivers-edge soils. There is slight polish on the handle-end, likely ground smooth either for preserving the lashings used or due to slight movement of the head over the period of service (years?). The finder walked a Mississippian village site for years, his collection had four broken spades (the bit ends, not the heels); each showed heavy use polish. A neat piece, lifetime guaranteed authentic in every detail. Shipping is $13.00, checks or M.O.s are welcomed, however I do not use paypal--Roy A.