Is zakat obligatory on gold designated for adornment, weighing 150 grams, and if so, is it due after a year has passed from the date of knowing the ruling on zakat, or from the date of its purchase?

There is no obligatory zakat on a woman's gold designated for adornment, according to the more preponderant opinion among scholars, which is the view of the majority. However, if the gold reaches the nisab (85 grams or more) and the wife wishes to adopt the view that zakat is obligatory on it, which is more cautious, then zakat becomes due on it after the completion of a full lunar year from the time she acquired it. The amount of zakat is a quarter of one-tenth (2.5%) of its total value.