Noting the increasing price of gold and the declining price of oil, TIME’s Bill Saporito offers the following observation:

But ask yourself, How useful is gold compared with oil? Gold doesn’t power your home or car or business. It isn’t a primary ingredient in anything other than jewelry. True, tiny amounts of gold show up in electronics and computers, but it’s not strictly necessary. If you want to own a precious metal that can do some heavy lifting, try silver, which has terrific antibacterial properties, or platinum, which is rarer than gold and critical for stuff like catalytic converters for automobiles. Gold is a default choice in gifts that men buy for spouses or girlfriends, right up there with diamonds (another expensively silly hunk of the earth’s mantle). Its defining characteristic is scarcity, which has made it the repository for stored value for centuries. Yet if all the gold turned into Tootsie Rolls tomorrow, society could still run, albeit with more dental problems.

Substitute water for oil — metaphorically, of course — and you might recognize Adam Smith’s diamond-water paradox.

The things which have the greatest value in use have frequently little or no value in exchange; on the contrary, those which have the greatest value in exchange have frequently little or no value in use. Nothing is more useful than water: but it will purchase scarce anything; scarce anything can be had in exchange for it. A diamond, on the contrary, has scarce any use-value; but a very great quantity of other goods may frequently be had in exchange for it.

Want to learn more about Adam Smith while getting a good laugh? Read P.J. O’Rourke’s take on Smith’s classic The Wealth Of Nations.