Numismatics Question

[Sean Manning]

Thanks for that very complete reply, Paullus. (And if you asked Mr. Mattingly, thanks to him!)

It is rather technical; I’m making a hobby of collecting ancient and medieval prices for some things including metal. But I’m finding out some interesting things, like how big these Roman copper/copperalloy coins were! I used to imagine a sestertius as something like a modern penny, but now I know it was much larger and thicker.

For completeness, here is the whole Augustan system:

1 Gold Aureus (122.9 gr; 7.96gm) =25 denarii=100 sestertii =400 Asses
1 Gold Quinarius(61.46 gr;3.98 gm)=12.5 denarii=50 sestertii=200 Asses
1 Silver Denarius(61.46 gr;3.99 gm)= 4 sestertii = 16 Asses
1 Silver Quinarius(30.73 gr;1.995 gm =2 sestertii = 8 Asses
1 Orichalcum/Brass Sestertius (1oz) = 4 Asses
1 Orichalcum/Brass Dupondius ( 1/2 oz) = 2 Asses
1 Copper As/Aes (2/5 oz) = 1/4 sestertius
1 Copper Quadrans (1/16 oz) =1/4 As/Aes

The ratios are not market place values, but set artificially at:
Gold to Silver at 1:12.5
Silver to Orichalcum/Brass at 1:28
Silver to Copper at 1:45
Brass to Copper at 28:45 ( almost 5:8 )

Gold and Silver were struck almost pure and very true to standard weight; Brass and Copper much more carelessly at so many to the pound.
The Orichalcum/Brass was 80% copper:20% zinc and appears to be a natural alloy obtained first from the Bergomate territory in Germany, and later from Mons Marianus in Spain. The Copper was struck almost pure.

Humh … that does look like a suspiciously high value for copper. Copper tended to be worth 150-200 times less than silver in the ancient world. Of course, if it was too much over-valued, you’d get people lining up to sell their scrap copper to the senate’s mints!