Diameter vs. Weight vs. Thickness

The first chart shows the diameter of a coin plotted against its weight. The colour of the points represent the denomination of that coin and the size of these points reflects the thickness. Some denominations like the Roman denarii are relatively consistent in diameter, weight, and thickness – though differences exist for Republican vs Imperial, as well as by Emperor. Other denominations, particularly those based on the drachm, have much more variability due to the share extent of kingdoms and cities that minted these coins on different weight standards across many hundreds of years.