Tall man. The 999 silver sold by the silver shop on the third floor of Guofang Department Store in Lanzhou is pure, and the purity of 999 is 99.9%. Quality assurance, after testing by industrial and commercial bureaus at all levels, has been officially authorized and protected. The purity of silver is very high. Lanzhou, referred to as "Lan" and "Gao", was called Jincheng in ancient times. It is a prefecture-level city and provincial capital under the jurisdiction of Gansu Province, a second-class big city approved by the State Council, an important industrial base and comprehensive transportation hub in northwest China, and one of the important central cities in the western region.