Pt990 refers to the platinum jewelry with platinum content of 990%, which bears the imprint of Pt990 and belongs to the highest purity platinum.
Gold is generally divided into 10K, 14K, 18K and so on. Generally 10K =10/24 = 0.4167, which means that the gold content of10k is 4 1.67%. It shows that the gold content of 14K gold is 58.33%. Similarly, the gold content of 18K = 18/24=0.75, and the gold content of 18K is 75%. 24K is pure gold.
Jade, also known as jade, jadeite, jadeite and Burmese jade, is a kind of jade, and its color is emerald green (called emerald) or red (called jade).
In the world, diamonds are usually measured by weight (carat), color, clarity (transparency) and cutting standard. 4C for short is the first English letter of carat, color, clari and cut.
The weight of diamonds is calculated in carats, 1 carat = 0.2g, 1 carat = 100 minutes.