Why is a "dot" of the word "jade" placed in the middle?

The word "jade" is a combination of "king" and "three", which means "entering the king's waist". The pronunciation of "jade" is the same as "domain", which refers to the land owned by the king.

Oracle Bone Inscriptions's word "Wang" and "Yu" are completely different, because the original meaning of word creation is different. The original meaning of the word "king": the biggest tomahawk, replacing the invincible commander in chief on the battlefield. The original meaning of "jade" is a rare gem strung together with silk rope. When it comes to inscriptions on bronze and seal script, the word "Wang" and "Yu" are basically the same, which is the result of simplification. Since the official script, in order to show the difference, the word "jade" has been added.