Pronounced wu (level tone). According to the "Erya" (Boya), kun (琨) is a stone next in quality to jade. The "Guangyun" states that kun (琨) is a beautiful stone. Additionally, the "Yupian" records that kun (琨) is also the name of a type of sword. In the "Jiyun," it is sometimes written as "珸." Etymology: [The "Jiyun," "Yunhui," and "Zhengyun" mark it as e'hu qie (讹胡切).] The "Zhenghui" has been corrected to "Zhengyun" in accordance with the original text.