Gold and Silver which has been Mixed with other Metal
Issue No. 1624- If gold and silver coins in which more than usual quantity of another metal is mixed are not called gold and silver coins, and if their pure gold or silver reaches the taxable limit, zakāt should be paid on them. However, if one doubts whether they have reached the taxable limit or not, it is not obligatory to pay zakāt on them; if he can test them to ascertain the quantity, the obligatory precaution is to do so.