Authenticating genuine Lalique pieces involves inspecting the item for precise signature markings, which vary by production era, such as etched script signatures for early vintage works or acid-stamped stamps for later crystal pieces. Authentic items exhibit exceptional weight, flawless clarity, and the signature contrast between polished clear surfaces and velvety satin-finished frost. Counterfeits often lack the crisp detailing, proper manufacturer hallmarks, and refractive brilliance characteristic of authentic French artisan production.