Moroni 7:14 says:
Wherefore, take heed, my beloved brethren, that ye do not judge that which is evil to be of God, or that which is good and of God to be of the devil.
On the other hand, if it does not interfere with direct worship, I have a hard time labeling it as a graven image. In that case, it simply becomes a religious symbol - and religious symbols are both important and powerful reminders of deeply held faith and commitment. If a friend were to give me a cross, for example, as an expression of their realization of how important Jesus is to my faith, I would have no problem wearing it as a token of that faith - and I would be grateful for the feeling and recognition behind the gift. It certainly would not constitute a graven image in how I would use it.
(Thank you, MH, for prompting me to count my published posts and realize this is #300.)