De Beers is no longer a monopoly and controls roughly 50% of the market: http://en.wikipedia.org/wiki/De_Beers#Diamond_monopoly

> On the marketing side, De Beers hired advertising firms, starting with N.W. Ayer in the late 1930s, to render axiomatic the idea that diamonds = true love."

Irrelevant to anyone except history buffs. Want to learn how Christmas started?