The Frome Hoard is old news; the article dates from 2010 shortly after the hoard was found. It now has its own
Wikipedia page which contains a detailed breakdown by emperor of the hoard contents as analysed so far.
As for the question in the thread title: it cannot be denied that there are similarities between ancient coins and fossil fuels. There's only a finite amount of them in the ground to start with, our technology and techniques for finding them and digging them up are constantly improving and more and more people are out there looking. It only stands to reason that sooner or later, we're going to run out.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis