Creation or Treatment Method: A diffusion treated zoisite that creates an artificial tanzanite
Identification Tools Required: Magnification, Chelsea filter, calcite dichroscope, refractometer.
How to Identify:
Primary Tests: Just as with the dyefusion treated andesine and tourmaline, the immersion cell will provide the diagnostic test in most cases. It should be noted that smaller stones that take the treatment more uniformly can be quite difficult to identify. But for the majority of the stones reviewed so far the incomplete color penetration of the diffusion material creates color zones that offer diagnostic results as per the images below.
Secondary Tests: At this time the ISG Community is researching additional identification methods to help in the verification of this material.
Repair and Setting: Requires very careful handling. Although this is a zoisite and requires normal care as would any tanzanite, the process of the treatment is not totally understood. As a result the increased fragile nature of this stone is not fully known at this time.