How do you measure ancient coins?

CarlWohlforth

I was asked how many grams and how many milimeters an ancient silver coin was. It seems simple to weigh the coin. However it isn't very round so how do I figure the diameter? Do I measure across the longest dimension? the shortest? Take an average?

tbirde56

You could relate the widest and narrowest, for example, 22-24 mm.

coachleonard

I usually reply to such queries with something like "It's 'bout the size of a quarter."

CarlWohlforth

Thanks for the replies! I may use both approaches

earlwbollinger

Ancient hand struck coins, go primarily by weight.
They would make up a bunch of planchets and weigh them carefully. The size and shape of the planchets was not as important as the weight.
Then they would heat them up to almost melting temp, and hand strike them using a hammer and dies on a anvil.

Of course during the latter Roman Empire days, inflation was going pretty rampant, so the coins composition would change.
Less silver in the denarius coins, more copper. Then as it got worse, they would use a copper core and plate them in silver. Then the plating got less and less, until they just quit doing it.

Many ancient coin books give the weight of the coin making it easier to identify later.

BigAlan

The method of striking Ancients tends to leads to off-center strikes. The actual method used two people, the malleator (hammerer) and the suppostor (underplacer). Worry about fingers would tend to make "Quality Job Two."