I am doing a project on Mesopotamia and have stumbled upon their currency system. They have Gerahs, Shekels and Minas. These units of currency are referred to by their laws, yet I can only find pictures of the Shekel on google images. The other coins only come from other civilizations. So my question is did Mesopotamia have physical coins to represent Gerahs and Minas or were they just measure of weight?