A monumental 104.39-carat cushion-cut tanzanite is the star of this eye-catching pendant. The gem has been certified by the American Gemological Laboratories (AGL) as being untreated, meaning that no clarity or thermal enhancements have been used to achieve its vivid purplish blue color. Virtually all tanzanite stones are heat treated, so a perfect untreated stone such as this one is an extraordinary find. As its certification states, "The unusual combination of size, provenance and quality…