People often say that there are two kinds of platinum, one is PD-Pd (worthless) and the other is true PT-Pt. Now both of them are 990, and there were 950 before ~
Color gold, rose gold and tricolor gold are 18K gold with different colors. Because it is crossed or added with other metals, it will fade after taking it for a long time ~
On value, only gold is valuable and of good quality ~