Keygems

Australian Zircons

Natural white and brown zircons
The blue zircons have been heat treated. The best bue is thru' the C axis but the natural xtal shape makes it difficult to get the best colour from the rough.
Some of these stones were treated 20 years ago, some have reverted back to original colour but most have retained their blue colour.

Also be aware that the blue may not be stable, may fade in sunlight, and you could lose the blue if too much heat is used when dopping the stone, so keep it cool, best is cold dopping.