Sunan an-Nasa'i 5280

أَخْبَرَنَا الْقَاسِمُ بْنُ زَكَرِيَّا، قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ، عَنِ الْحَسَنِ، - وَهُوَ ابْنُ صَالِحٍ - عَنْ عَاصِمٍ، عَنْ حُمَيْدٍ، عَنْ أَنَسٍ، قَالَ كَانَ خَاتَمُ النَّبِيِّ صلى الله عليه وسلم مِنْ فِضَّةٍ وَفَصُّهُ مِنْهُ ‏.‏

It was narrated that Anas said:"The ring of the Prophet [SAW] was of silver, and its stone (Fass) was made of silver too