The colour 'emerald' refers undoubtedly to the green gemstone and to the connection with nature. Therefore, both the colour and the valuable stone are a symbol for love, eternal youth and vitality. A married couple's 55th anniversary is hence called the emerald wedding anniversary, on which the partners give each other a jewel with an emerald. By the way, the emerald's green colour is due to the presence of chromium in the beryl mineral.