Chocolate might be the most delicious material ever devised. It was originally created as a liquid drink that could compete with coffee and tea. But people naturally make hot chocolate simply by letting a chunk sit on their tongue. This is because cocoa butter’s melting point is just below body temperature.

Cocoa butter is a remarkable product, rivaling dairy butter and olive oil—and surpassing them both in some aspects. Because cocoa butter’s melting point is near body temperature, it is an ideal moisturizer. It’s used in high-end lotions and facials. It’s also a key ingredient in some soaps, candles, and polishes. And, unlike butter, whose base is milk, cocoa butter shelf life is impressive.

Harvard University has conducted a number of studies and concluded that people who eat dark chocolate regularly and in modest quantities tend to live longer. This remains an area of research, but the opinion that chocolate is categorically bad for you is no longer taken seriously. In many countries, militaries include dark chocolate as part of the ration: it’s a sweet caffeine energy boost that replenishes the fat lost in intense physical exertion. A more controversial thesis is that dark chocolate can even take the edge off of sexual frustration.

Dark chocolate is a wonder of human ingenuity, no less impressive than steel or concrete. We have managed to transform a nasty, bitter rainforest nut into a cool, solid, delicate substance that melts in the mouth and trips the brain’s pleasure centers like few things can. It is the materials science equivalent of poetry, beautiful and subtle.