De Beers reveals diamond secrets as parent firm Anglo American opens up

De Beers, the diamond producer that has made secrecy a cornerstone of its business for more than 120 years, is pulling back the curtain to help bring more lustre to its owner Anglo American.

Anglo, a London-based miner of copper, coal and iron ore, hosted a 90-minute presentation for investors and analysts that revealed information De Beers has never made public before: where its best diamonds come from and how much they fetch per carat, for example.

Providing a better view of the diamond unit, acquired from the billionaire Oppenheimer family in 2012, may help convince investors that Anglo shares are the best way to gain exposure to a commodity that has gained about 75 per cent in the past five years, outperforming any of the other major products the company mines.

"Shareholders' best interests are served by transparency, disclosure and openness," said Jeremy Wrathall, head of global natural resources at Investec, who sees De Beers as the hidden jewel in Anglo's crown and values the unit at US$20 billion.

Anglo is not getting the recognition it deserves for De Beers, according to Wrathall. The unit provides about a fifth of the company's revenue and a quarter of its earnings.

The company's earnings have been buoyed by diamond prices that have gained about 75 per cent in the past five years as the United States recovered from the financial crisis and China's burgeoning middle class started to share the West's love affair with the precious stones. Anglo forecasts that global diamond demand will climb to US$31 billion in 2018 from US$25 billion last year.