Why it is sought after
It attests to a rarer natural state on the market and requires precise documentation: photos, dimensions, color under various lights, and gemological control.
JOYZANITE GUIDE
Unheated tanzanite: natural, rare, nuanced.
An unheated tanzanite retains its original expression. It is not necessarily blue: it can be yellow, green, brown, grey, violet, very dark brown, or almost black. This complexity attracts collectors seeking a less standardized stone.
View the unheated stonesCertification
Independent certification is particularly relevant for an important unheated stone or one intended for a collection.