The town of Mererani in northern Tanzania is the only place in the world where tanzanite is found. This deep blue gemstone is said to be a thousand times more rare than diamonds and sells for thousands of dollars in America and Europe's glitzy boutiques.

But on any given day, several thousand young children will descend into Tanzania's treacherous mines. Often they are only paid if find a slither of gemstone.

Reporter Richard Lough met 12-year-old Godlisten Mollel, who describes working conditions in the mines and the alluring beauty of tanzanite.

Music for this show ...