Sam Kean

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.

I learned to be a hot-air balloon pilot to take tourists over the Masai Mara Reserve in order to earn some money and finance the work I was doing with my wife, Anne. We were studying the life of a family of lions for more than two years. Taking pictures was a way to capture information we could not put in words.