Wu Collection, Lower Volume Radical: Stone (shí) 磯 Kangxi strokes: 17 Page 836, Entry 01 Pronounced ji The Jade Chapters (Yupian) defines this as a sandbank or reef in water. The Extended Rhymes (Zengyun) states that when stone causes water to churn, it is called a reef (ji). Mencius (Mengzi) states: This cannot be provoked. The Commentary (Shu) states: The term ji refers to agitation or splashing. It describes stone causing water to churn by following the current and agitating it. Also, the Jade Chapters (Yupian) defines this as to polish or grind.