Should the value of gold that has not reached the threshold for zakat be combined with money that has reached the threshold, in order to pay zakat on both together, or should zakat be paid only on the money?

Current banknotes are treated like gold and silver; they are combined with them to complete the nisab. Gold is combined with cash or trade goods, and zakat is obligatory on all of them if a lunar year has passed since their ownership. The nisab for banknotes is the equivalent of 85 grams of gold or 595 grams of silver, and the amount due is one-quarter of one-tenth (2.5%).