The Prophet ﷺ had a ring made of silver with an Abyssinian stone, and engraved on it was "Muhammad, Messenger of Allah."
أخبرنا العباس بن عبد العظيم العنبري قال حدثنا عثمان بن عمر قال حدثنا يونس عن الزهري
أن النبي ﷺ اتخذ خاتما من ورق فصه حبشي ونقش فيه محمد رسول الله
Reported by Bukhari, Clothing, Chapter (47), Hadith: 5868, and Muslim, Clothing, Chapter on the silver ring with an Abyssinian stone, Hadith: 2094, from the hadith of Yunus bin Yazid Ayli, through him, and it is also in Kubra, Hadith: 4513.