100% gold or 24 karat gold is remarkably soft for a metal. This softness allows for gold’s ductility (its ability to be drawn into wires) and malleability (its ability to be hammered into sheets). In fact, Gold is the most malleable metal that mankind knows of, and it could be hammered into sheets so thin that a pile of them an inch high would contain more than 200,000 separate sheets.
While gold’s softness allows it to be easily beaten into sheets and drawn into wires, it also has its downsides. One of the most common uses of gold is in jewellery, wherein intricate designs of golden ornaments are studded with precious jewels. It is almost impossible that a jeweller would use 100% gold in an ornament that needs to tightly grasp onto a diamond or some other precious stone. The reason for this is the exceptional softness of gold that we spoke about earlier. 24 karat gold is so soft, that it could easily be deformed and lose its firm grip on a jewel and allow it to slip or fall out of your ornament. Hence, order to have an ornament that is stronger. most jewellers use 22 karat gold which is an alloy.
Gold comes in varying levels of purity; from 10 karat gold – is the lowest purity to 24 karat gold, which is 100% pure. Gold of less than 24k is always an alloy with other metals, such as copper, silver or platinum.
An alloy exhibits properties of all the component metals within it. For example, mixing 2 parts of silver with 22 parts of gold would give us an alloy that is 22 karat or 91.67% pure gold and would be a lot harder than 100% pure gold as it would take upon the harder properties of the silver. as the percentage of gold decreases, the strength/hardness of the alloy increases, according to the properties of the other metal(s) in the alloy.
Gold alloys for jewellery are created both to create a harder, more durable metal to work with and which will better withstand the rigours of daily wear, so you can be assured your jewellery will still be as beautiful many years later.