The seal of the Messenger of Allah ﷺ was made of silver, and its stone was part of it.
حدثنا محمود بن غيلان حدثنا حفص بن عمر بن عبيد الله الطنافسي حدثنا زهير أبو خيثمة عن حميد
كان خاتم رسول الله ﷺ من فضة فصه منه
[Sahih]. Abu Dawud also narrated it in the chapter on rings, the section on adopting a ring, no. 4217, and Nasai, no. 5203, both from the hadith of Zuhayr through this route. Bukhari narrated it, no. 5870, along with others, from the hadith of Mutamir from Humayd from Anas through this route.