Discover the history of precious, semi-precious, and organic gemstones, their scientific properties, their mythical powers, and their traditional uses.Humans have been beguiled and fascinated by gemstones and crystals since prehistory, and made use of them for everything from currency and ceremonial decoration to tokens of love or power. But why have some been considered more significant than others - rare or otherwise?Learn all about the key characteristics of precious and semi-precious stones, and discover the science behind some of their more unusual and mysterious properties, and the various ways in which they have taken on powerful symbolic meanings.How did the Vikings use iolite to help them steer their ships, for example? And why did the Ancient Greeks and Romans believe that sardonyx could protect them in battle?