Watch SafeHorology glossaryDefined term / crystal
Crystal
The transparent cover over the dial, made of acrylic on most vintage watches, mineral glass on many affordable ones, and scratch-resistant synthetic sapphire on most modern luxury watches.
Authentication note
Why this detail matters.
The crystal material has to match the reference's era: a sapphire crystal on a watch made decades before the brand adopted sapphire indicates a replacement, and possibly more. On date models, magnifier strength is a checkable spec, since counterfeit cyclops lenses commonly magnify noticeably less than the genuine article. Scratch behavior differs too, because acrylic scuffs and polishes out while sapphire almost never scratches.