Sunan Abi Dawud Book 36, Hadith 10
A man came to the Prophet (ﷺ) and he was wearing a signet-ring of yellow copper. He said to him: How is it that I notice the odour of idols in you? So he threw it away, and came wearing an iron signet ring. He (the Prophet) said: What is it that I see you wearing the adornment of the inhabitants of Hell? So he threw it away. He asked: Messenger of Allah, what material I must use? He said: Make it of silver, but do not weigh it as much as a mithqal,
The narrator Muhammad did not say: " 'Abd Allah b. Muslim," and al-Hasan did not say: "al-Sulami al-Marwazi."
The Prophet of Allah (ﷺ) disliked ten things: Yellow colouring, meaning khaluq, dyeing grey hair, trailing the lower garment, wearing a gold signet-ring, a woman decking herself before people who are not within the prohibited degrees, throwing dice, using spells except with the Mu'awwidhatan, wearing amulets, withdrawing the penis before the semen is discharged, in the case of a woman who is wife or not a wife, and having intercourse with a woman who is suckling a child; but he did not declare them to be prohibited.
Abu Dawud said: Only the transmitters of Basrah have transmitted this tradition.
The signet-ring of the Prophet (ﷺ) was of iron polished with silver. Sometimes it remained in my possession. Al-Mu'ayqib was in charge of the signet-ring of the Prophet (ﷺ).