How to Write 硇 (náo) — Meaning “Sal ammoniac”

Imagine a stone (石) that is as salty as the sea (卤 sounds like 'nao' in English). This mental image helps you connect the stone radical with the salty mineral meaning of náo.

Pay attention to the right side 卤: it has a vertical stroke inside the box, not a cross. The left radical 石 should be slightly narrower, and the whole character should be balanced horizontally.

硇 (náo) is a specific mineral salt, while 砂 (shā) means sand or small particles of rock. 砉 (huā/xū) describes a sound like tearing or cutting. Visually, 硇 has the inside structure 卤, unlike 砂 which is 石+少 and 砉 which is 石+㐄.

硇 is mostly used in technical terms like 硇砂 (sal ammoniac) in chemistry or traditional Chinese medicine, and in place names like 硇洲 (Naozhou Island in Guangdong). It is a rare character not found in HSK vocabulary, so learners may only encounter it in specialized contexts.

Common words containing 硇 include: 硇砂 (náo shā) — Sal ammoniac; 硇洲 (náo zhōu) — Naozhou; 硇水 (náo shuǐ) — Nitric acid.