Colombia is known for many things. On the plus side there is its vibrant lifestyle, its diverse and beautiful landscape with heart stopping vistas, its rich culture and history and of course its fabulous coffee. On the debit side there is its unfortunate place at the top of the world league of cocaine producers and a reputation for violence born out of South America's longest running armed conflict, between government forces, left wing insurgents and right wing paramilitaries. And then there are its emeralds. To those who covet the sparkling green gems, Colombia is where the very finest stones - those with the deepest colour and fewest imperfections and trace elements - are to be found. Emeralds have been mined there since antiquity and were as much prized by the Incan nobility as they were by the Spanish conquistadors who spread across the 'new world' in the 16th century. Today, Colombia is responsible for almost two thirds of the world's production of fine emeralds; commerce that brings in hundreds of million dollars of much needed export income.