I'm sorry, but I cannot be certain of anything from these fotos.
To form an opinion I would need to examine physically with magnification at least.
I have seen a similar effect when I have used industrial quality arsenic on a blade.
I am not suggesting that this has been used here, but the colour of iron can vary depending upon many factors, one of those factors is uncontolled impurities in substances which come into contact with the blade material.
|