The 875 stamp stand for purity of the gold. 24kt gold is 100% pure gold,23kt gold is 95.8% pure,22kt gold is 91.60% pure and 21kt gold is 87.50% pure. This purity is obtained … when you calculate (24kt/ 21kt) * 100 = 87.50%.11 people found this useful.hat is the meaning 916 kdm in gold?  KDM: Gold Jewelry from some places is / was marked with a KDM stamp  which means that the Jewelry was soldered with Cadmium.