Economics
The Economic Paradox of the Diamond-Water Gap
Quick fact
In a desert, a bottle of water may cost more than a diamond of similar weight, while in a city, water is nearly free but diamonds remain expensive—proving that price depends on context and availability, not just usefulness.
Why this is interesting
You can live for days without a diamond, but you'd die without water. So why is a tiny diamond worth thousands of times more than a gallon of water?