Ruling on selling old gold for new gold

Question: The questioner / L. H. from Makkah al-Mukarramah asks and says: I went to a gold seller with a set of old jewelry, and he weighed it and said its price was 1,500 riyals. I bought new jewelry from him for 1,800 riyals. Is it permissible for me to pay him only the difference of 300 riyals, or should I take 1,500 riyals and then give him 1,800 riyals together?

Answer: It is not permissible to sell gold for gold except like for like, exactly the same, weight for weight, hand to hand, by the explicit text of the Prophet (peace and blessings be upon him), as reported in the authentic hadiths, even if the type of gold differs in terms of newness or oldness, or other types of differences. The same applies to silver for silver.
The permissible method is: the one who wants to buy gold with gold should sell his gold for silver, or other paper currency, and take possession of the price, then buy his need of gold at its price in silver or paper currency hand to hand; because paper currency is treated as gold and silver in the application of riba in selling some of it for some of it, and in selling gold and silver for it.
As for selling gold or silver for something other than currency, such as cars, goods, sugar, and the like, there is no harm in separating before taking possession; because riba does not apply between gold and paper currency, and between these mentioned items and their like. And it is necessary to clarify the term if the sale is on credit; because of His saying, the Exalted: [al-Baqarah: 282].