The Value of the Nisab in the Zakah of Adornments

The third and final question in the letter from the sister Khamriyyah from Iraq, in which she says: I own a gold piece valued at ninety dinars, and I bought it when prices were low. What is the amount of zakah due on it, and is it true that zakah must be paid on it every year? Please inform us, may Allah reward you.
Answer: Yes, the correct view is that it is subject to zakah. There is a disagreement among the scholars; some scholars hold that gold and silver adornments are not subject to zakah. However, the stronger and correct view is that they are subject to zakah if they reach the nisab. Therefore, this adornment you have is subject to zakah, and the amount is one-quarter of a tenth. From every one thousand, it is twenty-five; if it is worth two thousand, it is fifty, and so on, one-quarter of a tenth. This is how the Prophet (peace and blessings be upon him) explained it.
It is obligatory for the one who has an adornment that reaches the nisab, when a lunar year has passed over it, to pay out one-quarter of a tenth of its value. One-quarter of a tenth is twenty-five in the thousand, fifty in the two thousand, and so on. Yes.