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."

أَخْبَرَنَا أَحْمَدُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا مُوسَى بْنُ دَاوُدَ، قَالَ حَدَّثَنَا زُهَيْرُ بْنُ مُعَاوِيَةَ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، قَالَ كَانَ خَاتَمُ النَّبِيِّ ﷺ مِنْ فِضَّةٍ فَصُّهُ مِنْهُ .