ENOfficial
It was narrated that Anas said: "The ring of the Prophet (ﷺ) was made of silver and its stone (Fass) was made of silver too."
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا مُوسَى بْنُ دَاوُدَ، قَالَ حَدَّثَنَا زُهَيْرُ بْنُ مُعَاوِيَةَ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، قَالَ كَانَ خَاتَمُ النَّبِيِّ صلى الله عليه وسلم مِنْ فِضَّةٍ فَصُّهُ مِنْهُ .
sunnah.com