Just How Many Coins Are Out There?

[Suda]

On average, how many coins are there of any one specific type? I recently got a coin of Julius Caesar (Venus, Aeneas carrying his father "CAESAR") and I've been curious about how many coins of this type or any other type are in existence today.

[Andrew McCabe]

Of that specific type, probably 500 in near FDC, and perhaps 5000 in ordinary nice condition - better than VF or about EF with no problems. Several known hoards and other unpublished hoards account for at least 1000 EF examples. One might extrapolate that there are 50,000 of that type in poorer condition. Likely several million were struck. Survival rates of well-published coins in "nice condition" from my personal observations of rare types typically amounts to maybe 20 per die, or about 1/1000 of what was originally made. In poorer condition you can multiply those numbers by 10. For many coin types, millions were struck, so thousands of attractive specimens surviving is not unusual. Yours is not a rare type. Overall, for nice condition ancient coins in the current marketplace, one has think tens of millions of available examples. After all one single market venue alone has nearly half a million individually described ancient coins on offer. Forum has probably thousands currently for sale. And what's on offer today amounts to a tiny percent of ancients coins in collections and jam jars around the world. There's probably enough ancient coins around for everyone on the planet to have a nice example. Billions.

[areich]

You'd have to research and estimate the number by type. This type is common enough that it would be a great amount of work to count even the examples published.

It's only truly rare coins where the number is given as an absolute and that is often (perhaps even always) wrong. If you find one example published in a reference book you might call yours the second known example (which many collectors and some dealers would do). Or, depending on how hard you look, you might find it's the 3rd, the 6th or the 12th. And that would still leave out the examples in private or unpublished museum collections.

You can use relative rarity, either from a feeling you developed if it's your speciality or from rarity ratings published in reference books. You'd have to see how these are generated to judge how reliable they are. Sometimes they are just a wild guess.

[SC]

As Andrew has said, lots.

Though rather removed from Roman coinage, one area where we do have surviving records is medieval China.  There the copper "cash" coins were cast in astounding numbers.  The high point was reached during the last phase (the Yuanfeng period, AD 1078-1085) of the rule of the Northern Song Emperor Shenzong (ruled AD 1067 - 1085).  The cash coins were measured in strings - each string was a thousand coins.  While I don't have my copy of Harthill's book handy with the stats if I recall correctly the average for the Yuanfeng period was about 5 million strings per year which equals five billion coins per year!

Happily not all coins were as common as this but it is safe to say that ancient coins were struck, and cast, in far greater numbers than most people realize and survive in similarly huge numbers.  Anyone who has collected for any length of time will have at least some experience of people making remarks along the lines of "Wow.  I didn't know there were any of those outside museums.  They must be very rare and valuable."  and are surprised to learn that the well worn (i.e. near slug) sestertius or as I usually have in my suit pocket is worth less than the coffee they are drinking.

Shawn