The Ring of the Prophet (peace be upon him)

It is sunnah for a man to wear one silver ring on his pinky finger. If it has a stone, it is sunnah for it to face inwards towards his palm, out of emulation of the Prophet SAWS. There is no explicit reference on it's size, color, or shape of the stone. It is not a fard act and there is no evidence that a Muslim is required to wear one. One must also be careful not to fall into shirk by believing in an object to have any sort of power or blessing in it.

 
The Ring of the Prophet (SAWS)
Anas b. Malik reported that Allah's Messenger (peace be upon him) wore a silver ring on his right hand which had an Abyssinian stone in it, and he kept its stone towards the palm.
Sahih Muslim Book 024, Hadith Number 5223

Imam al-Nawawi said in his commentary on Sahih Muslim: "The scholars say an Abyssinian stone means a stone of onyx [ in which there is whiteness and blackness] or carnelian ('aqiq) because their mines are in Abyssinia and Yemen, or it is said [it means] that it's color was Abyssinian (i.e. black)."
Yahya Bin Sharaf al-Nawawi, Sahih Muslim Bisharh al-Imam Abi Zakariya Yahya Bin Sharaf al-Nawawi (Beruit: Dar al-Fikr, 1995), 7:58-59.

Some of the scholars among them al-Suyuti also said that Abyssinian means a kind of chrysolite with a greenish color which exists in the lands of the Abyssinians. Abdullah Bin Sa'eed Muhammad 'Abbadi al-Lahji, Kitab Muntaha al-Sul 'Ala Wasa'il al-Wusul Ila Shama'il al-Rasul, 3d. ed. (Beruit: Dar al-Minhaj, 2003), 1:540.

This prophetic tradition is rigorously authenticated and one explanation for an Abyssinian stone is that it was carnelian ('aqiq), but it should be noted that there are no prophetic traditions which have been authenticated stating that the prophet, Allah bless and grant him peace, wore a carnelian ring. Shaykh Abdullah al-Lahji said in his commentary on al-Nabahani's Shama'il: "Everything that has been transmitted of prophetic sayings concerning carnelian rings, indeed none of it is authenticated; even if it's chains of transmission are numerous as the Hafiz Ibn Rajab said [Allah have mercy on him]."  ibid., 1:541.

Commentary researched by Shaykh Abdul-Karim Yahya, SunniPath Academy Teacher


History
Narated By Anas b. Malik : The Apostle of Allah (peace be upon him) 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 Apostle of Allah."
Abu Dawud Book 029, Hadith Number 4202

The tradition mentioned above has also been transmitted by Anas through a different chain of narrators. This version as transmitted by 'Isa b. Yunus adds: It remained in his hand until he died, 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 into it. He ordered to take it out, but it could not be found.
Abu Dawud Book 029, Hadith Number 4203

Narated By Ibn 'Umar : The Apostle of Allah (peace be upon him) took a signet-ring of gold, and put the stone next the palm of his hand. He engraved on it "Muhammad, the Apostle 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 Apostle of Allah." Then Abu Bakr wore it after him, then 'Umar wore it after Abu Bakr, and then 'Uthman wore it after 'Umar till it fell down in a well called Aris.
Abu Dawud Book 029, Hadith Number 4206

Right Hand
Narated By Ali ibn Abu Talib : The Prophet (peace be upon him) used to wear the signet-ring on his right hand.
Abu Dawud Book 029, Hadith Number 4214

Left Hand
Narated By Abdullah ibn Umar : The Prophet (peace be upon him) used to wear the signet-ring on his left hand, and put its stone next the palm of his hand.
Abu Dawud Book 029, Hadith Number 4215

The Weight
Narated By Buraydah ibn al-Hasib : A man came to the Prophet (peace be upon him) 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: Apostle of Allah, what material I must use? He said: Make it of silver, but do not weigh it as much as a mithqal (4.235 grams).
Abu Dawud Book 029, Hadith Number 4211

Etiquette
Narrated Anas ibn Malik: When the Prophet (peace be upon him) entered the privy, he removed his ring.
Abu Dawud Book 1, Number 0019

It is prohibited to wear a ring in the middle finger and the one next to it.
'Ali reported: Allah's Messenger (peace be upon him) forbade me that I should wear a ring in this and that finger of mine, and he pointed to the middle finger and the next one.
Sahih Muslim Book 024, Hadith Number 5229
Also see Abu Dawud Book 029, Hadith Number 4213

Why it may not be a sunnah
Some scholars say that wearing any ring is not Sunnah since the prophet Muhammad (peace be upon him) used to wear a ring for signing letters sent to other kings because they told him that kings would not accept any letter that has not been signed. Hence, Scholars say it is sunnah for those who use it to sign papers and documents and some say it is Sunnah even for normal people - this is by scholarly opinion only.

•     Hanafi: For Rulers, it is Sunnah.
•     Maliki: It is permissible and recommended to wear a ring since you want to imitate the prophet (peace be upon him) . and Haram if you wear a ring to show off
•     Hanbli: It is permissible and NOT recommended
•     Shafi: Sunnah for Rulers and Normal muslims

Note: In Sahih Bukhari and in Sunan Abu-Dawud, the ring of the Prophet (peace be upon him) was of silver, and its stone was of silver too. Some researchers provide references that the Prophet  (peace be upon him) may have owned more than one ring. Allah knows best.