: "Sightholders" (authorized buyers) were offered "boxes" of diamonds at a fixed price with no room for negotiation . If a buyer refused a box or tried to resell rough stones elsewhere, they were blacklisted from future sales. 2. Marketing: "A Diamond is Forever"

: During economic downturns, like the Great Depression, the cartel would withhold supply and stockpile diamonds to keep prices from falling.

The cartel's primary goal was to ensure diamonds remained expensive despite being relatively abundant in nature.