Since ancient times, the purest thing in the world is crystal. It is often compared by people to a chaste girl's tear, the stars in the summer night sky, the wisdom of a saint, and the essence of all things on earth. People have also given precious crystals many beautiful mythological stories, entrusting symbols, hopes, and unsolved mysteries to it. When it comes to crystal bracelets, we must first understand the types and classifications of crystals.