How to calculate the zakah on gold jewelry containing stones that are not gold

You say: I own some gold jewelry, including a gold set, but it contains many stones that are not gold. Do I pay zakah on the weight of the entire set, or only on the weight of the gold, excluding the stones? And if the gold is eighteen karat, how do I pay its zakah?
Answer: You must pay zakah on the gold only, based on its market value. You pay zakah on the gold only, but there is no zakah on the stones or diamonds if they are for use. If the gold reaches the nisab (minimum threshold for zakah) of eighteen karat or higher, it is subject to zakah. The nisab is twenty mithqals, which is ninety-two grams of gold, equivalent to eleven and a half Saudi pounds. If it is less than that, there is no zakah on it. Yes.