Q: Is Zakah (obligatory charity) due on diamonds
used for adornment?
A: There is no Zakah due on the diamond or
pearls used for adornment. When they are used for trading purposes, it is
obligatory to pay Zakah on them. With
regard to gold and silver, Zakah is obligatory on them even if they are used for adornment when they
reach the Nisab (the minimum amount on which Zakah is due).
~
Source: Fatwaz of Ibn Baz, volume 14, Part No. 14;
Page No.123, Chapter on Zakah on gold and
Silver.| https://www.alifta.net/fatawa/fatawaDetails.aspx?languagename=en&View=Page&PageID=2577&PageNo=1&BookID=14
