A short, honest history of diamonds.

Diamonds aren't rare. They were rare. Until 1866, the world supply came from a few small Indian and Brazilian river deposits that had been worked for centuries — total annual production was a few thousand carats. Then a 15-year-old boy named Erasmus Jacobs found a 21-carat stone on the bank of the Orange River in South Africa in 1866. Within five years, the Kimberley diamond rush was producing 50× the entire historical supply per month.

The investors who controlled the South African mines — De Beers Consolidated Mines, formed in 1888 — had a crisis. Diamonds were now common, and prices were collapsing. So they did two things that defined the modern diamond market.

First, they cornered supply. By 1900 De Beers controlled 90% of global rough production. They held back inventory in their London "sights" and released it slowly to keep prices high — a textbook supply cartel that operated for over a century.

Second, they invented the diamond engagement ring. In 1947, De Beers hired N.W. Ayer & Son advertising agency to manufacture demand. Ayer wrote the slogan "A Diamond Is Forever" and seeded it everywhere — movies, magazines, society columns. They invented the "two months\' salary" rule (it was originally one month; they pushed it up over the next two decades). Within a generation, a custom that hadn't existed in 1939 was being treated as ancient tradition.

The cartel held until the late 1990s, when Russian production from Yakutia and Australian production from the Argyle mine came online outside De Beers\' control. By 2000 De Beers\' market share had dropped to ~50%; today it's under 30%.

The end of monopoly didn't end the marketing. Retail diamond prices have stayed roughly stable in real terms because the demand the cartel created is genuine now — generations of buyers grew up assuming diamonds were precious. But the resale market has always told the truth: diamonds resell for 30-50% of retail. They're not an investment; they're a culture.

Lab-grown diamonds (commercially viable since 2018) are the real long-term price disruptor. They\'re chemically identical, retail at 80% less, and supply is unconstrained. The market will eventually re-price natural stones around their actual rarity rather than around the marketing inheritance. That\'s already starting to happen at the lower end.

None of this means diamonds are a bad purchase. They\'re a beautiful, durable, symbolically loaded object. It just means: don\'t treat them as an asset, and don\'t treat the cultural rules around them (three months\' salary, "she\'ll know if it\'s less than a carat") as ancient — they\'re mid-20th-century ad copy.