Gold leaf is gold that has been hammered into thin sheets by goldbeating and is often used for gilding Gold leaf is available in a wide variety of karats and shades The most commonly used gold is 22karat yellow gold Gold leaf is a type of metal leaf, but the term is rarely used when referring to gold leaf The term metal leaf is normally used for thin sheets of metal of any color that do not contain any real gold Pure gold is 24 karats Real yellow gold leaf is about 917 pure gold Silver colored white gold is approximately 50 pure gold Layering gold leaf over a surface is called gold leafing or gilding Traditional water gilding is the most difficult and highly regarded form of gold leafing It has remained virtually unchanged for hundreds of years and is still done by hand Gold leaf is sometimes used in art in a raw state, without a gilding process In cultures including the European Bronze Age it was used to wrap objects such as bullae simply by folding it tightly over, and the Classical group of gold lunulae are so thin, especially in the centre, that they might be classed as gold leaf It has been used in jewellery in various periods, often as small pieces hanging freely From the ancient temples to modern day buildings, gold leaf has been an integral component of architecture to designate important structures since the dawn of humankind Due to golds resilience, goldendomed buildings can stand up to weather, deterioration and even modern pollution, keeping them beautiful sites for generations