If you were given an hour and a half to look at a rock and find an emerald in it, could you do it? Gemstone cutters from Jaipur have been doing this for generations and they could go through piles of ...

Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter. The four Cs — colour, cut, clarity and carat, a system invented by DeBeers in 1939 — guide the pricing of ...