14K White Gold Tanzanite and Diamond Ring 3.15 Carats Designed by Christopher Michael14 karat white gold ring by Christopher Michael set with one 3. 15 carats round brilliant cut tanzanite, blue violet vivid color, VS clarity, cut grade excellent, measuring 8. 7 mm wide, 8. 7 mm long, 6. 1 mm deep; with very good polish and very good symmetry. The proportions of the tanzanite are as follows: total depth 70%, table width 50. 5%. Tanzanites are color enhanced by heating. The overall quality rating of this tanzanite is 935 out of 1000.