the only way I know to repair a burned diamond is to have it repolished by
a diamond cutter. The surface has actually changed, like a piece of wood
burning, it has to be sanded… The good part is, the diamond probably
won’t lose any discernable weight, the bad part is, it’ll probably cost
you at least $80/ct. (or more)
Now here’s a trick I’ve seen some bench hands do with melle, and I don’t
suggest it works, but I’ve actually seen it work and I can’t explain why.
Coat the melle with boric acid and get it real hot, then throw it into the
pickle. Do this over and over until the burned surface is gone. Yeah I
know it doesn’t work, but I’ve actually seen it work. Go figure.