Gold Karats Explained

Gold Karats: Not to be confused with carats (a measure of gemstone weight) or carrots (a delicious root vegetable), Karats with a K are used to measure the purity of an item containing gold. What does this mean??

 Vintage yellow gold wedding band with a typical "14k" stamp to indicate its gold content. 

Vintage yellow gold wedding band with a typical "14k" stamp to indicate its gold content. 

Gold is an elemental metal, meaning that gold molecules cannot be reduced to a simpler form through normal chemical methods. In its 100% pure state, gold is too soft to be practical for use in jewelry.

To get the wonderful color and texture of gold without sacrificing on strength or durability, jewelers  almost always alloy, or mix, gold with a stronger metal. This is where karats come in: they tell us how much pure gold is contained in an alloy.

One karat = 1/24th of the total mass of a gold-alloy object (don’t ask me why they chose 24). That means if an item contains 24 karats of gold, it is all gold! It is highly unusual to find jewelry that is 24 karat.

Today, the majority of gold alloys used by jewelers are standardized and come from large refineries. The most popular alloys used in the US right now are 18 karat and 14 karat.

If an item is marked 18 karats (18K), that means it contains 18 out of a possible 24 karats of gold. 18/24 = 0.75, so an 18k gold alloy is 75% gold and 25% other metals. 

So, it follows that 14K gold (14/24) equals approximately 58% gold and 42% other metals.

Working with antiques, we come across fabulous jewels made out of all sorts of alloys that are not as commonly worked with today. Pieces as high as 23K and all the way down to 9K frequently show up.

It’s easy to get caught up in the numbers when purchasing fine jewelry (we’ve talked about this before with diamond grading reports), but when hunting for the perfect antique piece, keeping an open mind about materials will seriously increase your options.

So don’t be deterred by a lower karat alloy – even Queen Victoria had a large number of pieces in 9, 10, & 12K gold in her collection. As the old saying (that I just made up) goes, if it’s good enough for the queen of England, it’s good enough for me!