Hadithcore
Mishkat al-Masabih, 4406

Malik said :

I dislike youths being dressed with any gold, for I have heard that God's messenger forbade wearing a gold signet-ring ; and I disapprove of it for men, both old and young. He transmitted it in <i>al-Muwatta</i>.

وَعَن مَالك قَالَ: أَنا أكره ن يُلْبَسَ الْغِلْمَانُ شَيْئًا مِنَ الذَّهَبِ لِأَنَّهُ بَلَغَنِي أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ نهى عَن التختمِ بالذهبِ فَأَنا أكره لِلرِّجَالِ الْكَبِيرِ مِنْهُمْ وَالصَّغِيرِ. رَوَاهُ فِي الْمُوَطَّأِ

References1 variant
In-Book Reference
Book 22, Hadith 96