At college I was acquainted with one of the family who told me a story about when one of his uncles was in Egypt and on a tour of the pyramids or some ancient site. The guide said they had unearthed some bronze chisels used for stonecutting and their scientists had no idea how the alloy had been made that hard and tough. The uncle thought to himself "I know...", and smiled. He said they keep it very closely guarded, and have for centuries.
I'm sure any competent chemist could figure it out (though it may be some destructive tests and it will cost more money than they are likely willing to spend. For that matter any competent metallurgist can give you a modern alloy that is likely better (alloys are of course a compromise so better in one area may be worse in a different one). Not that is matters as anyone today who wants to cut stone will use modern steel not bronze (unless they are trying to reproduce the old methods which can sometimes be valuable for understanding)
Of course there are better alloys today for all those specific uses (likely except musical).
It was just a comment on the oddity that what the Egyptians were using had not yet been figured out, but that he knew. Despite all our vast current knowledge, there remain bits of arcane knowledge still hidden away in obscure corners.
It's definitely NOT the case that "any competent chemist could figure it out".
He'd also told me about an MIT team who had gotten closer than others to figuring it out, but gave up after the mixes/processes kept exploding on them. Definitely no lack of competence there, but maybe they did run out of budget or motivation to keep unintentionally blowing things up. It's not as trivial as you'd like to think.
