This coin (a Daric) is approximately two and a half thousand years old, and was issued by Darius the Great, of Persia. It weighs about a quarter of an ounce (about $5 gold dollars or £1 gold pound). This Daric has held it’s value for more than two millennia, and even if melted down to simply provide its 98% purity level of gold, it would be worth about £265 paper fiat pounds. I would say that this means it has held its value for all of that prodigious length of time. I wonder what the current British paper-money pound will be worth, in terms of gold, in 2,500 years, given that it is already 1/265th (or 0.38%) of the value it held in 1931, a mere 81 years ago? One suspects not much.