Put pure carbon under enough heat and pressure – say, 2,200 degrees Fahrenheit and 50,000 atmospheres – and it will crystallize into the hardest material known. Those were the conditions that first forged diamonds deep in Earth’s mantle 3.3 billion years ago. Replicating that environment in a lab isn’t easy, but that hasn’t kept dreamers from trying.

Making diamonds in a lab is sure to upset the deeply entrenched diamond industry. 

The mystique of natural diamonds is anything but rational. Part of the allure is their high cost and supposed rarity. Yet diamonds are plentiful – De Beers maintains vast stockpiles and tightly controls supply. Clever marketing may bring buyers around to manufactured diamonds.

The hardest marketing will be up to husbands to convince their wives that the synthetic ones are just as good. 

Kevin Castro, a jeweler in Cedar City, Utah, comes to a surprised halt. “These are awfully pretty,” he says. I tell him that they are man-made and ask if that bothers him. “If you go into a florist and buy a beautiful orchid, it’s not grown in some steamy hot jungle in Central America,” he says. “It’s grown in a hothouse somewhere in California. But that doesn’t change the fact that it’s a beautiful orchid.”

So, is a diamond real if it’s made in a lab or only if it’s mined from the earth?