What is considered for the nisab of gold and silver? Is it by asking the jeweler about the purchase price or the selling price? And is it for 24-karat gold and pure silver? By what number is each multiplied to determine the nisab?

The zakat threshold (nisab) for gold is 85 grams of pure gold (24-karat). The nisab for other karats is calculated by adjusting the weight (e.g., for 21-karat, the nisab is 97.14 grams).

Once the gold reaches its nisab, one-quarter of one-tenth (2.5%) of it is to be given as zakat, either in gold or its equivalent cash value based on its selling price.

The zakat threshold for silver is 595 grams, and what is due on it is one-quarter of one-tenth (2.5%), to be given either in silver or its equivalent cash value.

The nisab for paper currency is measured against silver (595 grams), not gold. One should ask a jeweler about the value of 595 grams of silver to determine the nisab.