15 Carat 4X3 Oval Cut Tanzanite Natural Loose Gemstones Wholesale Lot w/ Beverly Oaks LLC Exclusive Certificate of Authenticity NATURAL REAL TANZANITE GEMSTONES WHOLESALE LOT FOR JEWELERS 15 CARAT 4X3 OVAL CUT TANZANITE HARDNESS 6.5 ON MOHS SCALE DECEMBER BIRTHSTONE