Glassy and lustrous gem Tanzanite crystal that is very gemmy from top to bottom. Complete and undamaged, highly gemmy, overall excellent quality. Natural, unheated gem Tanzanite crystal. Illustrated in the Sept.-Oct. 2009 issue of the Mineralogical Record (Figure 84, page 386). 13.2 carats in weight, 2.6 x 0.7 x 0.6 cm.