Musnad Ahmad 28:499

Surayj narrated to us, Abdullah ibn al-Mu'ammal narrated to us, from Ibn Abi Mulaykah, from Abdullah ibn Amr ibn al-Aas: That he wore a ring of gold, and the Messenger of Allah (peace and blessings of Allah be upon him) looked at it, as if he disliked it, so he threw it away. Then he wore a ring of iron, and he (the Prophet) said: "This is more evil and more evil," so he threw it away. Then he wore a ring of silver, and he (the Prophet) remained silent about it.