What is the ruling on buying 30 grams of gold jewelry for 30 grams of old gold, with the seller requesting an additional 5 grams for workmanship? Does the hadith "Gold for gold, hand to hand, like for like" apply only to gold currency and not to jewelry? Is it permissible to defer and pay the price in installments in this case?

The ruling on exchanging old gold for new, and selling gold on installment, has been previously explained. Ribā al-faḍl (usury of surplus) and Ribā al-nasī'ah (usury of delay) occur in gold jewelry just as they do in gold coinage. This applies to all types of gold and silver—their good and bad quality, their intact and broken pieces, their jewelry and raw forms, their pure and mixed varieties—and there is a consensus on this matter.