Vladimir Potanin

For a rich and reasonably successful guy, it is impossible not to enjoy your job; otherwise, why would you spend so much time and effort doing it? I am a great fan of Norilsk, and I like this kind of challenge.

The price of diamonds can vary greatly depending on size, cut, color, and other factors, including whether they have a history. But because of the rarity of blue boron diamonds, they often fetch more money than gems of similar quality.

And I think that still is true of this business - which is basically research and development - that you probably spend more time in planning and training and designing for things to go wrong, and how you cope with them, than you do for things to go right.