With the last Harry Potter film opening today, let Michael Spirito supply all of your Order of the Phoenix/ Death Eater jewelry needs. Made in sterling silver, gold, and precious stones, these are nice enough to horde at Gringotts, but you'd want to wear them instead.
If you are Dumbledore's, through and through:
If you've done your time at Azkaban and stand with The Dark Lord:
If you show up wearing these, I'll sit on the other side of the theater.
(It is the end of an amazing narrative trajectory that shaped a generation of kids. Ask one who is close to you what Harry Potter means to him or her- the answers are fascinating.)