A gallery handout picture supplied on June 6, 2007, shows Damien Hirst's Diamond skull on display at the White Cube gallery in London on June 3, 2007. The 50 million euros sculpture, that for most of its short existence has languished unseen in a secret high-security vault and has been deemed too costly to go on show, will be on exhibit at the Palazzo Vecchio in Florence, Italy, for the next five months. Three armed guards will be in attendance 24 hours a day to keep an eye on this controversial platinum-plated, diamond-encrusted human skull.