How is the Zakat on jewelry estimated: Is it estimated according to the current price of gold, or according to its value at jewelry stores after being evaluated as used?

Zakat on gold becomes obligatory when it reaches the nisab (minimum threshold) of 85 grams and a full lunar year (hawl) has passed on it. This is done by paying one-quarter of one-tenth (2.5%) of its value at the time Zakat becomes due, which is its price as used gold. Thus, a woman estimates the value of the gold she owns as used gold, then she pays one-quarter of one-tenth of it, i.e., 2.5%, by dividing the value by forty. Zakat becomes due every year based on its value at the completion of the hawl, not its purchase price.