Complete all around and perfect - This is a vibrant GEM tanzanite crystal of total clarity and has over 80% by volume of cutting-grade, gem rough content. The luster is glassy and the surface is smooth and very appealing. This is a top quality tanzanite thumbnail for the discerning collector, selected quite literally from a parcel of material destined to be cut. It is worth more than this price, I am sure, in retail value of cut stones - but would be a tragedy to facet into bits. Joe Budd Photos. Weight is 37.8 carats.