Abu Dawud Book 29, Hadith Number 4209.
Chapter : Abandonment of wearing signetrings.
Narated By Anas b. Malik : I saw a signet-ring on the hands of the Prophet (PBUH) only for a day. The people then fashioned and wore (rings). The Prophet (PBUH) then threw it away and the people also threw (them).
Abu Dawud said: Ziyad b. Sa’d, Shu’aib and Ibn Musafir transmitted it from al-Zuhri, ‘Ali said in their versions: “of silver.”