I reveal sapphire’s rich secrets including - what’s the most expensive sapphire ever sold? And why sapphires aren’t just blue? And even why your ‘something blue’ is so meaningful at weddings.
Let's celebrate opal, the birthstone for October, in all its vari-coloured guises. Looking through an electron microscope, you'd see stacks of silica beads that diffract white light into all its colourful wavelengths. But we don't need hi-tech to appreciate nature's creative beauty with our own eyes.