أَخْبَرَنَا أَبُو بَكْرِ بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا أُمَيَّةُ بْنُ بِسْطَامٍ، قَالَ حَدَّثَنَا مُعْتَمِرٌ، قَالَ سَمِعْتُ حُمَيْدًا، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ خَاتَمُهُ مِنْ وَرِقٍ فَصُّهُ مِنْهُ ‏.‏

It was narrated from Anas that: The Prophet's ring was made of silver and its stone (Fass) was made of silver too. Translation Not Available

Book Ref: Sunan An Nisai Book 48 Hadith 5199
Web Ref:  Sunan An Nisai Vol 6 Book 48 Hadith 5202