Xu Collection, Upper Volume Radical: Metal (jīn) Page 1306, Entry 01 Kangxi Stroke Count: 20 Pronounced xiù. Iron rust. Originally written as the variant form xiù. Also, according to the Correct Interpretation of Characters (Zhengzitong), mirror rust refers to the green rust on mirrors, commonly known as Consort Yang filth. Also, pronounced sù. The meaning is the same.