A currency, to be practical, needs to meet the following four characteristics: Be relatively scarce, be durable, be divisible, and be impossible to counterfeit.But to actually be a currency, a resource still requires that people treat it as such; i.e., that large numbers of people with no practical use for the physical embodiment of the currency accept it in trade for things of practical value. This means that, practically by definition, the currency thus acquires some amount of value in excess of whatever value it would have were it not a currency. This excess is effectively "imaginary value"--a mass delusion or self-fulfilling prophecy, albeit a useful one. If nobody uses it as a currency, it loses that value, no matter how well it could theoretically work as a currency.
Likewise, non-currency commodities can acquire imaginary value through various means--such as an expectation of future value, or arbitrary fads. Debt is 100% pure imaginary value, completely worthless but for the expectation that the debtor will repay it. Now, "imaginary" value is still value, and is real enough for most practical purposes, but is and always will be vulnerable to disappearing rapidly.
Fiat currency is a nearly worthless commodity with substantial imaginary value. Shares of a public corporation represent a fraction of the true value of the corporation's wealth, plus some amount of imaginary value. Gold is a more useful commodity than the article seems to think, but it's still likely that gold's value is at least half imaginary, based only on the perception of it as a store of value. Real estate also has substantial value, but that didn't stop it from (temporarily) acquiring massive imaginary value as well. It's worth noting that, assuming a secure system of tracking ownership, the title to a plot of land meets your characteristics even better than gold.
Yes, gold is likely to remain a de facto currency of choice, but don't kid yourself into thinking it isn't massively overpriced for exactly that reason.
If you actually want a durable store of almost entirely real value, that can't be faked or quickly created, bulk dried beans might be a good start.