Shama-il Tirmidhi Chapter 11, Hadith Number 1 (82).

Anas bin Maalik Radiyallahu ‘Anhu says that the ring of Rasulullah Sallallahu ‘Alayhi Wasallam was ,made of silver and the gem stone was from Abyssinia.

According to the majority of the ‘ulama it is permissible to wear a ring made of silver. The Hanafis say it is not permissible to wear a ring made of bronze. iron, steel etc. In the early stages, Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam did not have a ring made, until it was known that the kings of Persia and other countries did not accept or take into consideration letters that had no seal (stamp) on them. He had begun sending letters to the kings inviting them to Islaam. A seal (stamp) was made in the sixth or seventh year hijri. The ‘ulama give different opinions on the wearing of the ring. Some ‘ulama say that it is makruh for any person besides the king and judge to wear a ring. The research of the Hanafi ‘ulama (may Allah Increase their number and accept their efforts) in this matter, according to the saying of ‘Shaami’ is, that it is sunnah for the kings, judges, trustees and those who need a seal. Besides them it is permissible for others, but better not to use it. The reason is evident that Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam only made one when it became necessary, before he began sending letters to the kings. This will be mentioned in hadith number six in this chapter. Abu Daawud and others have stated that besides the kings, others are prohibited from wearing a ring. Since it has been proven that many Sahaabah Radiyallahu ‘Anhum wore a ring in the presence of Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam, and in other ahaadith that Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam had permitted it, this prohibition will be taken as that which is contrary to a more meritorious and desired act.