Cambodian Blue Zircon is the King of Zircon- but it doesn’t start out that way. Natural Cambodian Zircon is a dark brown and hard to see inside. To help predict how blue it might heat, one of the tests is to hold it up to the sun and look for flashes of red…those red flashes are a good indiction it will heat a nice blue, but there are no guarantees….
To achieve the blue, Cambodian Zircon needs to be heated in an oxygen reduced environment. What this means is that oxygen has to be kept out of the heating process in order for the chemical reaction to take place. This is done by burying the rough in charcoal inside a crucible before subjecting it to intensely high heat.
I’ll be posting a video later showing the entire process…but for now, please enjoy this short video of a crucible full of gems after heating