On Hold. Tanzanite Gemstone 6.25 CaratsOn hold being mounted in a ring. One 6. 25 carats marquise brilliant cut tanzanite, exceptional color, VS clarity, cut grade excellent, measuring 8. 8 mm wide, 17. 6 mm long, 6. 1 mm deep; with excellent polish and excellent symmetry. The proportions of the tanzanite are as follows: total depth 69. 3%, table width 52. 8%. The overall quality rating of this tanzanite is 975 out of 1000. Tanzanite is color enhanced by heating. Its rare to see a marquise