Can anyone tell me what the heat treating temperatures are for
Zoisite. I understand the process presents some amazing results.
Tom, if you mean the brown, transparent type of zoisite that is
heated to make it into blue tanzanite, it is generally heated to
1100F to 1200F (600C to 650C) to get that rich, velvety
violetish-blue. Some of the transparent green zoisite is also heated
in that range. This is they type of zoisite that grows in a crystal
structure, not the aggregate.
If, however, you mean the green aggregate type of zoisite like the
"ruby in zoisite", I have never heard of heat treating it for any
James in SoFl