The main differences in gold are color and karat. The color is determined by the additional metals in the gold alloy, and karat purity is determined by how much gold is in the alloy.
24K gold is pure gold, but is too soft to use in jewelry. When we talk about gold jewelry, we are typically referring to gold alloys with various purities. You should consider a variety of factors when deciding which gold purity is suitable for you. Lower karats (such as 10K) have less gold in the metal alloy, but tend to be more affordable and durable. Higher karats (such as 18K) have a higher ratio of gold in the alloy, but are softer and more expensive. 14K gold is a great middle ground between the two, which is why it is so popular in jewelry. However, don’t be afraid to go above or below that benchmark. For those who want a rich, luxurious looking gold, 18K is perfect for you. For those who are on a budget, 10K will deliver the gold you want at a lower price point.
One of the earliest gold alloys was invented in Ancient Egypt – a 50/50 blend of gold and silver called electrum. Today, we are still using silver in our gold alloys, with the addition of other metals to achieve certain hues.
YELLOW GOLD
Yellow gold is what most people think of when they think of gold jewelry. It is the closest in color to pure gold, and therefore has the longest history. Yellow gold is alloyed with silver and copper. When the pure gold content is higher, the alloy takes on a more saturated yellow hue.
WHITE GOLD
White gold is alloyed with either platinum, palladium, or nickel. Though an alloy of white gold was first developed in the 19th Century, it didn’t become commercially available until 1912. The jewelry maker Belais patented their own formula for white gold using nickel and zinc in 1920, and is credited with spearheading its popularity through the Art Deco era. Today, white gold is sometimes plated with rhodium to increase its brightness and strength.
ROSE GOLD
Like yellow gold, rose gold is alloyed with copper and silver, however with a different ratio of copper to silver, with some alloys containing no silver at all. With origins in 19th century Russia, rose gold has had many variations in hue over the years, ranging from coppery tones to a more dramatic pink cast. Learn more by reading our blog post on the evolution of rose gold jewelry.
GREEN GOLD
Green gold isn’t actually green per se, but rather yellow gold with a greenish cast. This green tone is achieved with the use of silver in the gold alloy, sometimes with additions of copper and zinc. Though the gold and silver alloy electrum was used in antiquity, green gold jewelry reached the height of its popularity at the turn of the 20th century in the Art Nouveau and Edwardian eras.
As you can see, white, rose, and green golds are no less “pure” than yellow gold, it is simply the additional metal content that varies. Many people know which colors they prefer, however there are a few guidelines you can use to help you find the right shade of gold for you. People with cooler undertones in their skin tend to be complimented by white gold, while people with warmer skin tones tend to look nice with yellow gold. If you have pink undertones, you may prefer rose gold, while people with olive undertones look beautiful next to green gold. Of course, there are no “rules” when it comes to choosing metals, and you should try on lots of different kinds to find your favorite.
If you’ve ever been to an estate jewelry store, you’ve likely noticed a difference between antique gold and modern gold. Gold alloys varied widely before the 20th century, and as a result, you will see hues and tones differ from piece to piece. As standards changed, gold alloys became much more uniform, and the gold you see manufactured today varies little, if at all, across jewelry makers. In general, antique gold tends to be warmer than modern gold, more coppery and less yellow in tone. The term Hamilton Gold is used to describe this antique rosy gold. If you find that modern yellow gold tends to not look good next to your skin, you may find that antique gold, with its pink undertones, is a much more flattering shade for you.
The marks on your gold jewelry can tell you its karat purity. Some marks, such as “14K”, are easy for the average person to identify. If you come across three digit numbers, they refer to the amount of pure 24 karat gold contained in the metal. So gold marked “585” is 58.5% pure gold, or 14 Karat. Here are some common marks and what karat purity they indicate:
“333” – 8K
“375” – 9K
“585” – 14K
“750” – 18K
“916” – 22K
NOTE: Marks will vary depending on the region where they were manufactured, for example, marks on gold jewelry manufactured in Ireland or the UK will say “CT” instead of “K”.
Sometimes the purity mark on gold jewelry is misleading or incorrect. For example the head of a ring may be 14K, while the majority of the piece is 10K, but the ring is marked only 14K. At Market Square Jewelers, we acid test all of our pieces to ensure the purity of the metal. Acid testing, also known as scratch or touchstone testing, is a simple method that involves scratching a special stone with the gold jewelry. This deposits some of the gold on to the touchstone, and various acids are then dropped onto it. Each acid is formulated to dissolve a certain gold purity, and thus you can determine which type of gold you are dealing with based on its reaction to the acid.