Is it rude to wear a star and crescent if you're not muslim?

I went to a store called Spencers and bought a choker. I didn't realize it was a star and crescent, used to symbolize Muslims and Iraq I believe. I'm sorry if I didn't get that right though. Anyway, it's a crescent moon with a star inside of it, just like the symbol. Is it rude to wear this if I'm not Muslim? Is it sort of like how people wear crosses when they aren't Christian? Someone please inform me of this, I don't want to offend anyone when in public.