Let me join to this interesting discussion for a while. According to the quote above I'll tell you a story from a Polish museum. It was probably in the 50's (I know it from the tales also, too young to remember
), when some metallurgist came to the museum and offered to examin excavated 11th century sword. Director, a very known Polish weapon scholar in those days, wasn't convinced about safety and legitimacy of such experience. But this metallurgist attained his goal promising to learn everything about this sword, mativated such examine as very important for Polish science, metallurgy etc. Then, with the director's permission in one hand and file in another, he just cut off 4 cm of the tang
After few weeks he send to the musuem a piece of paper with few notes of chemistry symbols with percents - something what should every classical scholar (this director was one of them) bring to heart attack. Nothing more. No age, no nothing - just inexplicable percents. To be honest I don't know what happened to this piece of paper with such important science results - I can imagine that director tread it into the ground
. Now this sword, with ugly cut tang, is visible on our arms and armour exhibition - for someones as a specific warning
Nowadays, as far as I know, there are non-invasive methods.
About the rust - I heard from reliable sources about fakers which are meaking very beautiful, old, deep corrosion
- so be careful
Best regards