The Chemical Properties of Gold

The task of buying jewelry today can be a bit confusing when it comes to the different types of gold available. There are many kinds of gold. There is white gold, yellow gold, rose gold, pink gold and even green gold.

Genuine gold will always start out yellow. The alloys, a metal that is created by combining two or more different metals when casting, will determine the outcome of its color. It is a fascinating process and takes much skill by a goldsmith to achieve. There are also many ways to “cast” gold into jewelry pieces.


Pure gold is generally too soft to be used for jewelry, so other metals are nearly always added to it, no matter which color of gold is being prepped for jewelry making. When examining a piece of jewelry, check to see what is stamped on the under-side of it. Most likely it will be marked 14K, 10K and often times, 18K. The “K” stands for Karat, which is a system used by goldsmith’s to determine how pure the gold is, in its mixture.


14K gold contains 14 parts of gold and 10 parts on another alloy or metal, making it 58% gold.

10K gold contains 10 parts gold and about 14 parts alloy or metals, making it a little over 41% gold.

18K gold contains 18 parts gold and 6 parts alloy, making it 75% gold.

12K gold contains 12 parts gold and 12 parts of another alloy, making it 50% real gold.

24K gold, the purest form of gold. It is 100% gold with no additives of any other alloys or metals. This form is often considered undesirable for jewelry as it is a very soft metal.

Playing around with the different alloys may seem like such fun, but it takes a great bit of experience and knowledge when working with these metals, some which are toxic if combined together and inhaled. Goldsmith’s often have a separate room where they create the different gold material. A gas mask is also used during this process and that of casting gold.

The method used is the exact method that will determine the color outcome of the gold. For example; Green gold is achieved by adding silver to gold. Rose or pink gold is achieved by adding copper to the mix. The more copper the richer the color.

Nickel (another alloy) is used when creating a white gold. Nickel can cause dermatitis in people who are sensitive to nickel though, so often times palladium, another metal alloy used to create white gold alloys is used for people with allergies to nickel. Palladium is similar to platinum and is more expensive than nickel, but is less likely to cause allergic reactions than nickel.

Often you will see “Black Hills Gold” advertised in your local jewelry store. Black Hills Gold jewelry is a good example of colored gold alloys. Most Black Hills Gold jewelry uses 10K or 12K gold alloys in shades of yellow, pink, rose, and green.