Total Transparency: 5 Watches with Sapphire Cases for See-Through Visibility in Every Direction

By Roberta Naas Just recently, Greubel Forsey unveiled its $1.3 million Double Tourbillon 30-Degrees Technique Sapphire watch. The entire case of this limited edition (8 pieces) watch was milled from a single piece of sapphire, revealing the 396-part movement. This watch is exemplary of the new direction many watch brands are taking when it comes to utilizing high-tech materials for watchcases.