Pave setting is most typically done with diamond or corundum stones
because of the inherent hardness of the stones. Tanzanite is not
nearly as durable and has a much greater risk of breakage when setting
in the pave style. During the pave setting the stones must be packed
in place in the metal with a brass pusher. Using 18k will make this
easier on the stone. Also there is traditionally a great deal of
graver work , raising beads and beading metal with beading tools that
stress the stones. I would expect that if you attempt this job to
expect about a 30% to 40% loss rate on the stones.
Tanzanite is not impossible to set , just not practical for anyone
but a professional stone setter.
JMA instructor GIA