Jewerly is frequently used as it is constantly worn and offers a simplistic yet inconsipcuous source for a magical item. I once wore crysal amulets around my neck, however ever time I charged the crystals with my energy, the cords would break the next day. Coincidence? Perhaps. All I know is that I don't have any more cords left to wear my crystals on, haha.
So yes, you can use objects for different purposes, whether it be jewerly, crystals, clothing, etc. However, as my advice to you, use a strong chain if you try to charge a cystal. ;)