Diamonds are of the earth, made billions of years ago, as old as the stars. They are an authentic, scarce product in an increasingly artificial world. Just as you cannot compare an original painting to a reproduction, you cannot compare a diamond to a synthetic. In fact, according to the Federal Trade Commission, "it is unfair or deceptive" to use the word "gemstone" to describe a laboratory-grown stone.
Jean-Marc Lieberherr, Antwerp, Belgium
The writer is chief executive of the Diamond Producers Association.