The simple answer to your question is, 'less'. 

But it's not as clear-cut as that. ;-)

You see, gold does not actually ‘tarnish’ or change color on its own.

Any discoloration that occurs on gold jewelry is caused by a reaction with a foreign substance has with one of the alloys added to the gold in order to make the finished jewelry.

Pure gold in itself is soft (you can actually reshape 24K gold with your hand), which makes it an impractical metal for wearable jewelry. In order to harden gold and make it more durable, it is mixed with other metals into an alloy. These metal add-ins (nickel, copper, zinc, palladium etc) make the gold hard enough for jewelry-making purposes. The more gold in the alloy, the higher the value and the less prone to jewelry tarnishing. The less gold in the alloy, the more other metal add-ins that can create the opportunity for the “gold” jewelry to become tarnished.  

We make and sell high-quality cubic zirconia jewelry from international precious metals standard gold alloys called 10K gold (41.7% gold), 14K gold (58.3% gold) and 18K gold (75.0% gold). 18k gold jewelry is less prone to tarnishing than 14k gold jewelry, due to the smaller percentage of other metals added in to the alloy. 14k gold jewelry is less prone to tarnishing than 10k gold jewelry for the same reason. 

What foreign substances can react with the other metals in 10k, 14k, or 18k gold such as that used in the jewelry we make and sell at CubicZirconia.com? 

In the rare case that your gold jewelry shows signs of tarnishing, it is most probably due to the alloy reacting with either your sweat, your skin’s natural moisture and pH level, or some other foreign substance such as lotion, sunblock, detergent or other similar substances.

On the other hand, over time any sterling silver jewelry piece exposed to air will tarnish by changing colors. Sterling silver is 92.5% silver and 7.5% other metals such as copper (which is often what’s responsible for color changing tarnish in sterling silver when it reacts to certain substances in the air). Therefore, when comparing sterling silver to gold, the sterling silver will tarnish more/more often. While jewelers have created some other substances similar to sterling silver but with different metal makeup and physical properties, anyone telling you sterling silver will not tarnish is lying or misinformed. 

The possibility of tarnishing is a big reason why we plate all our white metal jewelry (inclusive of white gold) with rhodium to add extra shine and to help protect the precious metals against wear and possible discoloration. Rhodium plating lasts for a few years, but not a lifetime. Eventually, in even the finest jewelry the natural (yellow) color of colored white gold or colored rose/pink gold will peek through, or tarnishing may occur. 

We provide an excellent care and cleaning FAQ which provides details on how to care for your cubic zirconia plus precious metals jewelry. 

In any case, if your sterling silver or gold jewelry begins to show a tarnish, a number of inexpensive commercially available jewelry cleaning products will be able to clean your jewelry and bring it back to its original luster if you don't wait too long. However, we strongly recommend that in cases where the tarnishing and discoloration is bad enough, that you get your jewelry professionally cleaned and rhodium plated for protection. The "Jewelry Spa Treatment" package we offer might be just the ticket.

Unsure about which precious metal to choose? Read our article, "Which Precious Metal Is Right For You/Her?