Ross-Simons - 6.90ct t. w. Sky Blue Topaz Vine Necklace in Silver. 18". On this unique necklace, 6.90 ct. t. w. sky blue topaz rounds garnish the tips of a sterling silver vine design. Emitting an angelic blue hue, the dispersed placement of the gems evokes a distinct elegance that will elevate all of your ensembles. Suspends from a rolo chain. Lobster clasp, sky blue topaz vine necklace. Blue Topaz birthstones are the perfect gift for December birthdays.