How big is a mina?

Could you please clarify for me the size of a mina? I'm interested in understanding the scale of this unit, as it seems to be mentioned quite frequently in discussions about ancient currencies and measurements. Is it comparable to modern units of measurement, or is it significantly different? Additionally, how did the mina evolve over time, and what were some of the historical contexts in which it was used? I'm curious to learn more about this ancient unit of measurement and its significance in the financial and cultural history of various civilizations.