It probably isn't a coincidence that a partially debased
Aureus exists right when the Crisis of the Third Century really took a turn for the worse. If the
Hostilian coin was minted after the battle of Abrittus, then it would have been during a time when Rome's finances and armies were stretched to their limit. Perhaps when
Diocletian (and later
Constantine) eventually introduced the
Solidus, he was aware that the
Aureus had been partially debased like the much more devalued
Antoninianus.
As Titanusus mentioned, we really need to see this sort of analysis on dozens of coins across several hundred years to draw a conclusion. If there was a downward trend during the Crisis, it would correlate to similar trends in
Roman silver until Diocletian's reforms.
There are two problems however. One, are we sure that X-ray analysis is the best option? For silver we know that the most accurate measurements for a coin's content are found when you look deeper than the surface. Since the technique in the topic post distinguishes the
obverse from the
reverse, it seems like it probably wasn't sampling the core. It's possible that production methods left residual silver or copper on the molds, hammers, etc that made the flans and coins, which might contaminate the surface a little
bit. It doesn't seem likely to be such a dramatic effect, but it's possible. The second problem is that it might be hard to get dozens of
Aurei for scientific experiments.
Quality measurements would probably cause some sort of damage to the coin.
Very interesting
thread!
