by Chrumps » Thu Mar 14, 2019 8:42 am
Four purities are long gone from Salem. Only one purity that matters is Aether.
Iron purity is average of leftovers in smelter and ore, so it is quite possible that putting same purity ore into smelter the results (if it happens to yield two bars) will be slightly different.
When dealing with ore of different purities it is best to have a number of smelters, each dedicated for certain purity range, so leftovers have less effect. Note that metal purity does not matter except for blades.