What is Mystic Topaz ? CAMEOS
'Mystic Topaz' is ''real" Topaz that is coated to add color. Much of the Topaz that is found in nature is in fact colorless, or 'white'. To add color, Topaz can be coated with an ultrathin layer (film), which is similar to the coatings used on camera lenses.
Such coatings can add a particular color to the treated stones, or, In the case of 'Mystic Topaz', the coating creates interference effects, displaying a rainbow effect of various colors. This effect may give the Topaz an artificial appearance (see photos), which sometimes causes confusion about the nature of the material.
The quality of the created rainbow effect in Mystic Topaz (is it really pleasing to the eye or not) and the visibility (or absence) of inclusions could determine the difference in quality between the individual stones.
Potential problems with Mystic Topaz:
Coatings can be scratched or damaged easily. It should therefore be handled with the same care as pearls for example. The coating is sensitive to chemicals and therefore one needs to remove the jewelry when doing household activities that include bleach for example or before going into a swimming pool.
Although Topaz is a hard substance, it can be cleaved rather easily and perfectly in one particular direction. Therefore, boiling in water or the use of an ultrasonic cleaner are not recommended when cleaning pieces of jewelry set with Topaz.
The particular rough in the second photo comes from the Elahera district, Sri Lanka, a locality where large chunks of colorless topaz are found.
Hanco Zwaan Ph.D., FGA
Netherlands Gemmological Laboratory
More on (Mystic) Topaz:
Best way to clean Mystic Topaz
Wikipedia on Topaz in English and Dutch
For those who are into it: Healing properties