Via Prashant Kothari
Chidanand Rajghatta's long series on the Gujarati diamond business is a great read; part 1, part 2, part 3, part 4.
Other parts of this series here.
My only lament is that there aren't any photographs. The Times of India resorts to some rather skanky illustration in lieu of an incredibly juicy photo essay. If I had the time and the resources, I would love to track a single diamond, from Africa to India, then from India to Belgium and onwards to New York City.