Zakat (Kitab Al-Zakat)
Dawud :: Book 9 : Hadith 1559
Narrated Umm Salamah, Ummul Mu'minin:
I used to wear gold ornaments. I asked: Is that a treasure (kanz), Apostle of Allah? He replied: whatever reaches a quantity on which zakat is payable is not a treasure (kanz) when the zakat is paid.