9ct gold is a popular alloy for the production of jewellery. The number describes the content of fine gold, which is 37.5% in this gold alloy. In addition to the pure gold, other alloying partners such as silver, copper or palladium are added, as the material is otherwise too soft and vulnerable to breakage. The jewellery is not only available in yellow gold, but also in rose and white gold. In this case, a certain ratio of copper and silver is responsible for the respective colouring. If 55.5% copper and 6% silver are added to the fine gold, the result is a delicate rose gold. If, on the other hand, 59% silver and 3.5% copper are added, the jewellery is given a white gold alloy. Another way of expressing 9ct gold is the term 9 carat.
