This is really amazing and beautiful: Chocolate etched with rainbow holograms using a technique that doesn't use additives of any kind, but rather carves specific microstructures into the chocolate's surface that defract light—much the same way that the security holograms on credit cards work.
Developed by Swiss design company, Morphotonix, working with a German chocolate mould manufacturer, the designs are etched onto a metal master mould, from which softer plastic moulds are pressed and are then filled with molten chocolate—not unlike how vinyl records are made.
While both milk and dark chocolate work, some specific varieties are incompatible with the moulding process (because physics). As Morphotonix CEO Veronica Savu explained to New Scientist, "We have been testing it with many types of chocolate. Sometimes it works great and sometimes no matter how hard we try it doesn't mould."
The hologram technology, which Morphotonix first began developing in 2012, has just been unveiled at the Interpack packaging trade fair in Düsseldorf, Germany. There's no word on when the these shiny, tasty treats will hit store shelves or when the moulds will be available for home chocolatiers.