Are gemstones counted as part of the gold when selling and buying?

Question : What is the ruling on a merchant who, when selling gold, weighs it together with the gemstone and turquoise and calculates it at the price of gold? And if he wants to buy this inferior or old gold, he weighs it without the gemstone or turquoise. Is this permissible, whether the customer consents to it or not?

Answer : All right, , if he sells the gold and includes these other metals in it, calculating them as gold, and when he buys it he does not calculate them as gold, this is permissible if the buyer is satisfied with it. However, he must not weigh the gold and what is with it as a single weight, because what is with it may be more than the gold and he calculates it as gold, or it may be less. And what I see is that it is better to say, for example, "this ring is for five thousand, one thousand riyals in total," than to say "the kilo is such and such" and weigh this gold with what is in it as if it were all gold.