Have you ever tried to sell a diamond?
- De Beers' advertising slogan, "A Diamond Is Forever," embodied an essential concept of the diamond invention. It suggested that the value of a diamond never diminishes and that therefore a diamond never need be sold or exchanged. This precept, of course, is self-fulfilling: As long as no one attempts to sell his diamonds, they retain their value ( assuming the cartel controls the supply of new diamonds). When, however, an individual is forced to defy this principle by attempting to sell diamonds, the results can prove illuminating. Consider, for example, the case of Rifkin's Russian diamonds.