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What Is Gold?

People love gold—and they have for a very long time. While the gold adornments preferred by Egyptian Pharaoh Tutankhamun (aka: King Tut) circa 1323 B.C. differ from those worn by today’s style influencers, gold is as prized now as it was then. It’s no wonder that ancient cultures all over the world forged gold into jewellery and structures to portray status and wealth. Today, gold is a very popular choice for engagement rings and other fine jewellery.

Gold Purity

As the most malleable of all precious metals, gold is an excellent choice when crafting designs with very intricate details. Plus, it’s resistant to rust, tarnish and corrosion. Pure gold is too soft for everyday wear, so it’s alloyed with a mixture of silver, copper and a trace of zinc, to give it strength and durability. This hardens the final product enough to last for many generations.

Karatage, denoted by a number followed by “k”, indicates purity, or how much of the metal in a piece of jewellery is gold. Karatage is expressed in 24ths, making 24k gold the highest karat gold. It has a rich and luxurious gold-yellow colour, but unlike 14k or 18k gold, it’s far too malleable for everyday wear. If you’re unsure what karat your jewellery is, you can find out by looking for a number followed by a lower case “k” stamped somewhere on the piece.


Gold is commonly stamped with what’s known as a hallmark. The hallmark indicates the amount of pure gold content, and sometimes denotes the date of completion and country of origin. And under federal law, gold jewellery must be accompanied by a maker's mark or registered trademark.

Blue Nile Gold

We carry jewellery that’s crafted in both 18k and 14k gold. Our 18k gold is an alloy of 75% gold with other metals to make it strong enough for everyday wear, and our 14k gold is an alloy of 58.3% gold and other metals. The minimum karat that is allowed to be sold as gold jewellery in the U.S. is 10k—an alloy of 41.7% pure gold. If you’re one of our European customers, you may be accustomed to a different gold karat scale. 585 is equivalent to our 14k gold, while 750 is the same as our 18k gold.

The Colour of Gold

Although it’s true that the colour of pure gold is yellow, gold jewellery or objects are almost always alloys. The metal they are alloyed with changes their colour to a variety of shades depending on:

  • The type of metal alloys included
  • The percentage of each metal alloy
  • The metals used to alloy gold, which include: zinc, copper, nickel, iron, cadmium, aluminum, silver, platinum and palladium

Our fine jewellery comes in 3 colours: yellow gold, white gold and rose gold.

What Is Yellow Gold?

A mixture of silver, copper, pure gold (and a trace of zinc) gives yellow gold jewellery its rich shine. Although the percentages of each metal used to create the alloy vary, all formulas starts with 75% pure gold for 18k gold and 58.3% for 14k gold. The result gives off a classic warm glow that makes an especially good setting for lower colour grade diamonds with a faint yellow tint.

If you’re interested in 14k yellow gold, which is slightly less rich in colour than 18k yellow gold, it’s important to note not only the difference in colour between the two karatages, but also the difference in durability and hardness. 18K is softer and will therefore show scratches more readily. 14K is harder which makes it a little more resistant to scratching.

What Is White Gold?

In order to give white gold jewellery its modern silvery-white colour, pure gold is often alloyed with a mixture of nickel, or palladium and silver, plus other whitening alloys. The piece is then plated (meaning it’s covered with a layer of another metal) with an extremely hard element called rhodium. While rhodium plating is relatively long-wearing, some occasional replating may be required. It’s not uncommon after a few years to see a slight champagne-coloured tint in your white-gold jewellery. This can be a sign that your jewellery needs replating to restore its original whiteness. We recommend routine cleaning and annual maintenance. Please contact our diamond and jewellery experts if you’d like to replace a ring purchased at Blue Nile.

What Is Rose Gold?

The romantic pink hue of rose gold jewellery is created by using a copper alloy. The more copper in the alloy, the rosier the hue. Rose gold has the same amount of pure gold as yellow or white gold. What’s different is the ratio of other metals that make up the remaining percentage of the alloy mix. Rose gold is a beautiful and unique choice for engagement rings, and its modern-vintage appeal has been a hot trend in the last few years. The preference of one karatage over another comes down to whether people want a lighter (18k) or slightly deeper (14k) rose colour for their setting or band.

What Type of Gold Does Blue Nile Use for Ring Heads?

For yellow gold and rose gold settings, Blue Nile uses platinum ring heads to secure centre diamonds. All designs in 14k white gold use 14k white gold ring heads which have the strength and durability required to keep a centre stone safe. 14k white gold is a very popular option with our customers as it has a similar look to more expensive platinum settings, but a more affordable price tag.

explore all gold jewellery

How Do You Determine the Price of Gold?

Gold is traded on a public exchange and therefore the price is subject to many external influences. That’s why the price of gold jewellery is largely dependent on three factors:

  • Purity of gold used (the karatage), combined with the physical weight of the item
  • Current market value of gold
  • Detail of the design and craftsmanship of the piece

Gold Karat Chart

24 karat = 100% gold

22 karat = 91.7% gold
Both 24k and 22k are considered too soft for fine jewellery, though prized and worn in some cultures.

18 karat = 75.0% gold
Considered to be the luxury end of fine jewellery.

14 karat = 58.3% gold
Ideal for fine jewellery, balancing wearability and value.

10 karat = 41.7% gold
Not available at Blue Nile.

What Karat Gold is Best?

The karatage that’s right for you may be a personal preference or a matter of budget. Both 14k and 18k jewellery from Blue Nile are sure to impress, so you don’t necessarily need to go for the higher karatage. Here are some factors to consider when deciding which to choose:

14k Gold

  • Good balance of durability and price because of the higher percentage of alloys used
  • Our most popular choice

18k Gold

  • Luxurious choice with a precious appeal
  • Slightly softer and less durable than 14k because of the higher amount of malleable pure gold in the alloy

Care Tips for Your Gold Jewellery

Prolonged or repeated exposure to chlorine or other chemicals in cleaning products can harm gold jewellery. We recommend that you remove your jewellery when gardening or cleaning to reduce abrasions and prolong the lustre. To clean gold jewellery, use a solution of warm water and detergent-free soap with a soft-bristled brush. Then, polish it with a specialized cloth or cleaning solution. When not worn, store your gold pieces in soft cloth bags or the original box to help prevent scratches.

Next: Learn More About Other Metals

Have A Question?

Contact us by phone at 00800-2583-6453 from Austria, 0800-098-8541 from the United Kingdom, or 00353-1-899-1351 for all other EU countries or email at
In addition, Live Chat is available during most business hours.