About 1200 years ago, ancient architects in the city of Samarra in the Near East built spectacular glass palaces – the largest and most lavish ever seen in the Islamic world . Now, chemists have discovered what the glasses contained, what made them translucent and how they differed from most pre-existing glasses available in the ancient world.

“They produced a colourless glass free of coloured taints simply by using a very clean silica source, which makes this group of glasses exceptional for the time,” says …