Xin (辛) — Yin Metal

Xin is yin metal — refined ornament, gold pin, jade-edged needle, surgical blade. Where Geng is raw iron eager to be hammered, Xin is the finished product that has already passed through fire and now dislikes returning to it. Xin Day Masters often have aesthetic sensitivity, attention to detail, an eye for craft, and pride in personal polish.

Xin pairs with 丙 in 丙辛合化水 — refined metal embracing yang sun and producing water, often interpreted as creative wisdom flowing from polished discipline. Xin fears excessive 丙丁 fire (it has been forged enough — more burns the finish) and welcomes clear water (壬) to keep the gleam.