[Currency] What was the conversion rate between gold and silver?

[QuintusSertorius]

I'm trying to work out how much a treasure horde would be worth in contemporary money. Specifically what a talent of gold is worth, compared to a talent of silver in 270BC.

I know that at the time, most currencies were based on silver, and a standard unit for a lot was the Attic talent (equivalent to 26kg of silver). One talent of silver was worth 6000 drachmae (each of which was about 4.4g).

What I'd like to work out is a conversion rate to assess the value of a chest-full of Persian gold darics.

I've had two contradicting conversion rates for silver to gold. One says a talent of gold is worth 20000 drachmae, so gold is about 3 1/3 times as valuable as silver. So roughly speaking, one daric is worth about six drachmae.

But I've seen another conversion rate saying one talent of gold was worth 27 talents of silver. Which would make each daric worth around 50 drachmae. Quite a difference.

So does anyone have any idea what the right conversion rate was?

[Molinaargh]

Just out of curiosity, do you intend to do anything with all this historical info? The military ranks, the clientage relations, now the currency. Are you writing something? Just curious!

[Atilius]

I believe that when the Romans began to regularly issue the gold aureus in the 1C BC, it was (at least by convention) worth 25 denarii. Over time, the denarius became seriously debased, so the relative value of the aureus climbed dramatically. Debasement was hardly a purely Roman problem, so valuation for any coin must take it into account. Unfortunately, the ancient sources might not be clear on that point.

[QuintusSertorius]

Just out of curiosity, do you intend to do anything with all this historical info? The military ranks, the clientage relations, now the currency. Are you writing something? Just curious!

Running a historical (tabletop/"pen and paper") roleplaying game set in 270BC. This is all stuff to help me get the basics right.

[stratigos vasilios]

Running a historical (tabletop/"pen and paper") roleplaying game set in 270BC. This is all stuff to help me get the basics right.

That sounds awesome!

[QuintusSertorius]

That sounds awesome!

I currently play WFRP 2e with my group, and we've played D&D4e and various variations of FATE (playing a Dresden Files game next), we're each getting a turn to GM something. I've checked with them and despite the fantastical nature of most games, they'd be happy for a change of pace by going historical. The Hellenistic age is ripe for roleplaying adventure, and barely covered by RPGs.

[QuintusSertorius]

I don't have sources for this, but someone else said elsewhere:

It seems that the Achaemenids and Hellenistic kingdoms had a similar ratio [to the Roman 1/14]. One gold daric weighed around 8.3 g, and was equal to 20 silver siglos weighing 5.5 g (110 g) or 25 Attic drachmae weighing 4.3 g (108 g).

That gives us a 1:14 gold:silver ratio, more reasonable sounding than 1:27.

[FriendlyFire]

In Appendix J (!) of "The Landmark Thucydides" (even if you ignore the text, it's almost worth it just for the appendices and maps), Thomas R. Martin says the gold/silver conversion rate during the Peloponnesian War (i.e. pre-EB time period) seems to have been roughly 13-14:1, which splits the difference between the two figures you cite. And he notes that the Greeks referred to the Persian 8.4-gram cold daric coins as "staters".

There's a complicating factor because the exact weight of coins varied between city-states. e.g. an Athenian drachma was 4.3 grams of silver, whereas an Aegina drachma was 6.1 grams. So, assuming a conversion ratio of 13:1, during the Peloponnesian war an 8.4 gram gold stater would have been worth just over 25 Athenian drachmae, or just under 18 Aegina drachmae. And if you're putting this into a story, Martin notes that moneylenders charged a fee of 5-7% :)

Edit: Herodotus also gives a conversion rate of 13:1, in para 3.95 where he's discussing the Persian kingdom.