Sorry - you cannot buy opaled badges anymore. There was a trend of them pre-1900, in the 1930s and then again in the 1960s. They are fragile and in the case that one falls out - it is difficult to replace them. I have spoke to Bur Patt and Masters of Design and they will never be able to offer them again - the cost is prohibitive - the badges would be at least $500 each. As an alternative, if your group allows, you might consider turquoise which is also very nice. ZTA offers this through MOD and is lovely!
There is always ebay but if your group never offered badges other than pearls (like DDD, DPhiE, AEPhi etc), you aren't going to find opaled ones ever only in our dreams
Denise