Day 6 - Symbol

Something that's very important in this main universum I'm creating are gemstones. There's a particular set of species that are known for their great power - in the past they've been used in everything - from craftsmanship, through science, up to warfare. Due to safety concerns in modern age, their use has been limited to use in a magical sport known as Jewel Dueling and decoration - everyone wears a tiny gem connected to their personality somewhere in their outfit of choice.