The image is a photograph of a signboard with Chinese characters written on it. The signboard is grey in color and has a red border. The text on the signboard reads "Arsenic-copper alloy" in both English and Chinese characters. Below the text, there is a list of the hardness of arsenic-coppers alloy depends on the content of arsenic in Europe and Central Asia, copper melting techniques were as follows: native copper-red brass-arsenic copper-bronze. In China, arsenic copper was mainly found in Gansu and Xinjiang in the region.