If you skipped the ?glass skin? Korean-beauty trend, which involved super-smooth, ultra-luminous skin, maybe the newest trend will be more appealing. Glass hair is popping up on celebrities from coast to coast. According to Allure, the trend is defined by a sharp cut and super shiny, straight, silky smooth tresses. It's little surprise it's become such a viral hit on social media, with celebs like Kim Kardashian West, Lucy Hale, and Jourdan Dunn all trying this look on for size.