ENOfficial
It was narrated from Anas that: The Prophet's ring was made of silver and its stone (Fass) was made of silver too.
Source: sunnah.com
Other translations
Arabic
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 .
sunnah.com