Items must be separated before being sold

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا لَيْثٌ، عَنْ أَبِي شُجَاعٍ، سَعِيدِ بْنِ يَزِيدَ عَنْ خَالِدِ بْنِ، أَبِي عِمْرَانَ عَنْ حَنَشٍ الصَّنْعَانِيِّ، عَنْ فَضَالَةَ بْنِ عُبَيْدٍ، قَالَ اشْتَرَيْتُ يَوْمَ خَيْبَرَ قِلاَدَةً بِاثْنَىْ عَشَرَ دِينَارًا فِيهَا ذَهَبٌ وَخَرَزٌ فَفَصَّلْتُهَا فَوَجَدْتُ فِيهَا أَكْثَرَ مِنِ اثْنَىْ عَشَرَ دِينَارًا فَذَكَرْتُ ذَلِكَ لِلنَّبِيِّ صلى الله عليه وسلم فَقَالَ ‏ "‏ لاَ تُبَاعُ حَتَّى تُفَصَّلَ ‏"‏ ‏.‏

Fadila b. 'Ubaid (Allah be pleased with him) reported: I bought on the day (of the Victory of Khaibar) a necklace for twelve dinars (gold coins). It was made of gold studded with gems. I separated (gold from gems) in it, and found (gold) of more (worth) than twelve dinars. I made a mention of it to Allah's Apostle (ﷺ), whereupon he said: It should not be sold unless it is separated.

Sahih Muslim 1591b https://sunnah.com/muslim:1591b