Musnad Ahmad 435:17

Isma'il narrated to us, he said: Khalid al-Hadhdha' narrated to us, from Maymun al-Qannad, from Abu Qilabah, from Mu'awiyah ibn Abi Sufyan, that the Messenger of Allah (peace and blessings of Allah be upon him) forbade riding on leopard skins, and he forbade wearing gold, except if it is cut/broken.