Hello, I am new to the list and new to serious stone collecting. I
have been told that Songea Sapphires heat nicely at 1200C for two
hours but have no other specifics. Does anyone have more than this or
any other observations on these stones. I also have some nice Umba
that has a pretty pink cast and some a brown/red cast. I am told this
could be treated to ruby. They are already cut. Can this still be done
and should I send them off to do it and if so to where?