Even though they changed their material strategy, with the added pressure to continue to offer ever-thinner and sleeker devices, Samsung didn’t want to also make their devices colder and less approachable. That’s why they developed, in-house, the sub-surface reflective coating that gives the GS6 and S6 edge its metallic- or jewel-like finish, which has the added benefit of being protected from scratching or marring itself thanks to being underneath the Gorilla Glass 4 outer surface.