The most common naturally-occurring colored diamonds are brown and are often called chocolate diamonds.
But yellow diamonds are not called lemon diamonds and red diamonds are not called cherry diamonds – what is the reason for the special moniker? It likely plays a marketing role, since brown diamonds are for some reason considered to be less desirable than others.
Because a large amount of the colored diamonds mined in Australia are brown – Argyle pink diamonds notwithstanding – the country has invested in a marketing campaign to improve their image in the minds of consumers.
It is believed that nickel impurities and lattice deformations are the prime causes of the discoloration. With this knowledge, scientists have learned to apply high-pressure, high-temperature treatments to brown stones in order to transform them into the more desirable yellow or colorless polished diamonds.For those that can’t be changed or sold as aesthetic diamonds, they can always be used for industrial purposes, and in fact often are.