The seal-ring of the Prophet ﷺ was made of silver, and its stone was part of it.
حدثنا موسى بن داود حدثنا زهير عن حميد
كان خاتم النبي ﷺ فضة فصه منه
Its isnad is sahih. Musa bin Dawud is Dabbi, Tarsusi, the judge, jurist, and ascetic. They criticized his memory, but that does not harm his reliability.Bukhari transmitted the hadith, 7/201, in the Book of Clothing, chapter on the silver ring. Abu Dawud also transmitted it, 4/423, no. 4214, in the Book of the Ring, chapter on what has been said about wearing a ring. Tirmidhi transmitted it as well, 4/199, no. 1740, in the Book of Clothing, chapter on what is recommended regarding the stone of a ring, and he said, hasan sahih gharib. Nasai transmitted it too, 8/173, no. 5198, in the Book of Adornment, chapter on the description of the Prophet's ﷺ ring.