Stunning sapphires, dazzling diamonds and red rubies abound in this week's sparkling edition of the Naked Scientists in which we find out how gemstones are formed, what makes them so beautiful and why they're so rare. We also reveal the tricks used by experts to flush out fake stones, and discover how synthetic diamonds can make better lasers, more powerful electronics, sweeter tweeters and cutting-edge scalpels. Plus, why a mongoose could be your best friend in a minefield, how a good breakfast leads to more male births and, in Kitchen Science, how to grow some beautiful crystals at home! Like this podcast? Please help us by supporting the Naked Scientists)