Origin

This character appears to combine a box shape (representing a container or enclosed space) with a dot, which most likely depicts red lead or cinnabar powder contained within a vessel. In ancient China, red lead and cinnabar were precious substances used in alchemy, medicine, and to make red pigments and pills, so the image of this powder in a container came to represent both the material itself and the reddish color associated with it. The character's meanings expanded from this concrete image to include the abstract sense of sincerity, possibly because red pigments were valued as markers of authenticity and importance in official documents and ceremonies.