I was working a Winter slash job clearing a site for a coal fired generation plant. The area had an open pit iron ore mine nearby. The first thing I noticed was pink snow and the Whiskey Jacks had red breasts and looked like Robins. One cut into a leaning Cedar immediately dulled my chain from the frozen iron dust that collected on the top side.bogydave said:Lots of glacier silt & volcano dust in all the trees here so they get dull eventually.