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Gold Jewellery

Due to its incredible lustre and other characteristics, gold is the most sought-after metal in the jewellery industry. This precious metal is naturally resistant to tarnish and corrosion. Most of all, gold has the rare quality of being dense yet still very malleable, which is ideal for crafting jewellery. Although the density of pure gold makes it heavy, it is still very soft, so alloy metals are blended with the gold to increase its strength and durability. The addition of alloy metals makes gold jewellery much more wearable and long-lasting, and also allows for the creation of coloured gold. Both 14ct gold and 18ct gold contain a percentage of alloy metals. Gold is available in three colours—yellow, white, and rose. All three colours are produced in the same way and have the same basic monetary value. White and rose gold are simply yellow gold blended with other metals to achieve their specific colour.

The majority of Costco’s jewellery is offered in two precious gold options: 14ct gold, 18ct gold. Discover the natural beauty and characteristics of each, and decide which one is best for you. All 14ct and 18ct white gold that Costco offers has been rhodium plated to enhance lustre, durability and brightness to the gold. This does not affect the percentage of gold in the item.

14ct Gold

14ct gold is comprised of 58% pure gold. It is blended with a higher percentage of alloy metals, which makes it lighter and substantially stronger than 18ct gold. Its strength makes it more durable and scratch resistant, and less likely to bend. 14ct gold wears well, and is often the choice for jewellery that is worn on a daily basis.

18ct Gold

18ct gold is comprised of 75% pure gold. It is blended with a lower percentage of alloy metals, which makes it heavier and softer than 14ct gold. Jewellery crafted from 18ct gold can be more susceptible to scratches. It also has a slightly warmer hue, which is appealing to many people.

Each piece of 14ct gold jewellery sold by Costco is hallmarked. Unlike our gold jewellery that includes gemstones or diamonds, our gold-only jewellery does not come with any type of paper authentication, such as a certificate or Article of Description. In the case of our gold-only jewellery, the hallmark itself, is the authentication.

!  More infomation can be found in the Assay Office Hallmarking Guide click here

Metal Care & Cleaning

Avoid all harsh chemicals such as bleach, ammonia, chlorine, hair spray and perfume, as they may cause permanent damage to metals. Do not wear your gold jewellery while using a pool or hot tub.

Gold jewellery can be cleaned using a solution of lukewarm water with a drop of mild soap. Place the jewellery in the solution, and let it soak for 10 to 30 minutes. If necessary, you can gently wipe the jewellery with a soft-bristle brush or cotton cloth. Rinse the jewellery thoroughly, and ensure that it is completely dry before storing. If you choose to use commercial jewellery cleaner, be sure to use one that is specifically designed for use on gold jewellery. Some solutions do contain chemicals that can cause permanent damage to certain metals, as well as sensitive gemstones and pearls. Use with caution.


You can easily maintain the beauty of your gold jewellery by having it polished by a jeweller. A basic polishing will remove any nicks and scratches, and restore its natural lustre. You can have your jewellery polished every 1-3 years, depending on usage. Over time, white gold can lose some of its lustre and bright white colour. You can restore your gold jewellery to its original brilliance by having a jeweller re-plate it with rhodium, which will give it a shiny protective finish that will last for years.