Not exactly the 'recommended way' to heat treat Burlington chert--as I never tried to clean the blackening I have no idea if some cleaning will restore the flint to its former appearance--somehow I doubt it--maybe you'll get SOME carbon removed, I couldn't guess how much, though--that's up to you, how much trouble you wan to go to. Where the big 3&13/16" by 1&7/16") Hardin isn't 'carbonated' it shows how the white flint turned a ruddy color--"brick color?)--the stem edges show basal grinding. There are a couple edge chips where the white Burlington color (off white) shows what's underneath. History: the piece is out of a Callaway County, MO collection--estate sale. Were the fire and the estate sale connected? I don't know, but I'll provide the history I have. The price reflects the condition. Shipping is $8.00, checks, cash, or M.O.s welcomed. I do not use paypal, though--Roy A.