Sale of Gold and Silver Against Gold and Silver

If gold is sold against gold, and silver is sold against silver, whether it is in the form of coins or otherwise, if the weight of one of them is more than that of the other, the transaction is haraam and void. If gold is sold against silver, or silver is sold against gold, the transaction is valid, and it is not necessary that their weight be equal, but if it is sold on credit or stipulated time, the transaction will be void.
If gold or silver is sold against gold or silver, it is necessary for the seller and the buyer that before they separated from each other, they should deliver the commodity, and its exchange to each other. And if even a part of the thing about which agreement has been made, is not delivered to the person concerned, the transaction becomes void.
If either the seller or the buyer delivers the stock in full as agreed, but the other person delivers only a part of his stock, and they separate from each other, the transaction with regard to the part exchanged will be valid, but the person who has not received the entire stock can cancel the transaction.
If silver dust from a mine is sold against pure silver, and gold dust from a mine is sold against pure gold, the transaction is void, unless one is sure that the quality of silver dust is equal to the quantity of pure silver. However, there is no harm in selling silver dust against gold, or gold dust against silver, as mentioned earlier.