Musnad Abu Ya'la al-Mawsili 118:1

Abu Khaythama Zuhayr ibn Harb narrated to us, Ibn Abi Uways narrated to us, Sulayman ibn Bilal narrated to me, from Yunus ibn Yazid, from Ibn Shihab, from Anas ibn Malik: That the Messenger of Allah (may Allah bless him and grant him peace) wore a silver ring on his right hand, in which there was an Abyssinian stone. And he used to place its stone toward the palm of his hand.