It is now scientifically possible to take X-ray images with a mobile phone or a digital camera, and to create these ghostly scans in almost all the colours of the rainbow.

And where making the crystals that turn X-rays into visible light used a highly toxic process that involved up to 1,700 deg C of heat, Singapore-based scientists can now safely create the crystals at less than 100 deg C - the temperature of boiling water - while wearing no more protection than a lab coat.