Abu Dawood

The Messenger of Allah (ﷺ) wanted to write to some persian rulers. He was told that they would not read a letter without a seal in the form of a silver ring on which he engraved "Muhammad the Messenger of Allah."

It remained in his hand until he died, in the hand of 'Abu Bakr until he died, in the hand of 'Umar until he died, and in the hand of 'Uthman. When he was near a well, it fell down in it. He ordered to take it out, but it could not be found.

The signet-ring of the Prophet (ﷺ) was of silver with an Abyssinian stone.

The signet-ring of the Prophet (ﷺ) was all of silver as was also its stone.

The Messenger of Allah (ﷺ) took a signet-ring of gold, and put the stone next the palm of his hand. He engraved on it "Muhammad, the Messenger of Allah". The people then took signet-rings of gold. When he saw that they had taken them (like his ring) he threw it away and said: I shall never wear it. He then fashioned a silver ring and engraved on it "Muhammad, the Messenger of Allah". Then Abu Bakr wore it after him, then 'Umar wore it after Abu Bakr, and the 'Uthman wore it after 'Umar till it fell down in a well called Aris.

Abu Dawud said: The people did not disagree on 'Uthman till the signet-rin fell down from his hand.

He engraved on it "Muhammad, the Messenger of Allah." and said: "No one must engrave anything in the manner of this signet-ring of mine. He then transmitted the rest of the tradition.

They searched for it but could not find it. 'Uthman then fashioned a signet-ring and engraved on it "Muhammad, the Messenger of Allah". He used to wear it or stamp with it.

Ziyad b. Sa'd, Shu'aib and Ibn Musafir transmitted it from al-Zuhri. 'Ali said in their versions: "of silver".