How to let him know you want...

So my SO and I have been together for almost two years. For Christmas I'm buying him a decently expensive present because it's something he would really love. I don't really care if I get anything back, and if I do I'll love whatever he decides to get me...but I secretly would love a nice necklace or piece of jewelery, but don't want to just come out and tell him because I don't want him to feel forced into buying me something. How can I let him know or hint to him that this is something I would like..?