While I love the idea of a crystal ring of any kind, metal beats it in two cases: 1. Crystals can shatter if stuck at the wrong angle (unlikely but possible).

While I love the idea of a crystal ring of any kind, metal beats it in two cases: 1. Crystals can shatter if stuck at the wrong angle (unlikely but possible). 2. Unlike a gold band the crystal ring can't be resized later in life.