Evil Eye is believed to be cast on someone with a simple malevolent glare.
It's no surprise or news that envy exists and even though you might think: "what can someone possibly envy of me", there's so much someone can want a trait (s) that you possess.
Obsidian is a powerful energgy protector, combined with the evil eye charm, it will let people know that your energy is protected.
Remember that it is very important that you don't try fixing your choker if it breaks, it just means that it's done absorbing the unwanted energy that was sent your way.
If you tend to have temper issues and it's usually caused by someone else, you want to have one of these chokers around.