The purity of 1 and 4 9s gold is 99.99%, and that of 5 9s gold is 99.999%. Therefore, the purity of Wujiu gold is high, and it is often called Wanjinjin.

2. In order to achieve higher purity, the manufacturing process of Wujiu Gold is relatively more complicated and strict. Compared with the production process of 49 gold, 59 gold needs to be purified and refined many times.

3. Because the purity and fineness of Wujiu gold are higher, it is more widely used. 49 gold is mainly used in jewelry, gold coins and other fields.

4. Because the manufacturing process of Wujiujin is complicated, its price is relatively high.