Did the ring that the Prophet (peace be upon him) wore and used to seal letters have any relation to his being married? Is it permissible to wear a ring with the intention of emulating the Prophet and clarifying one's marital status? And where did the Prophet wear it?

It has been clarified in previous fatwas that wearing a ring at engagement or marriage is a custom of the disbelievers, with no basis in Islamic law. Rather, wearing a ring in general is legislated, but not specifically for the purpose of marriage. The Seal of Prophethood was on the back of the Prophet, peace be upon him, and it has no connection to a ring used for letters.