Costco Diamonds

If you are in the market for an engagement ring, diamond earrings, or any other diamond jewelry, you should consider Costco. They offer high-quality diamonds and settings. Additionally, larger diamonds (1.00 carat or greater) come with a Gemological Institute of America (GIA) certificate, and the clarity and color of their diamonds provide optimal value (quality-to-price).

Reasons to Buy a Costco Diamond

Great Clarity

Diamonds are typically evaluated using four main criteria – color, cut, clarity, and carat. If you look at diamond jewelry from many of the common chain jewelry stores, the clarity is often rated at “I1” (included) or even lower. Costco’s diamonds are VS2 (very slightly included) or greater, which is 3 clarity ratings above these competitors. This clarity level is often where you get the greatest value. Paying for a higher level of clarity will increase the cost of the jewelry while providing minimal perceivable improvement to the diamond’s beauty. If you want to learn more about diamond characteristics, check out our “Buying a Diamond: The 4 Cs” article.

GIA Certificate for Diamonds of 1.00 Carat or More

GIA certification is the gold standard of diamond grading. If you want to be assured of your diamond’s characteristics and quality, you want a GIA-certified diamond. While not all diamonds from Costco are certified by GIA, any diamonds sized at 1.00 carat or greater come with a GIA certificate. However, even for stones under this size, Costco claims that GIA graduate gemologists carefully inspect the diamonds and utilize the GIA grading standards.

Setting Quality

Costco offers many engagement rings made from platinum. If your diamonds are set in platinum, you can rest assured that they will provide greater security than settings made with weaker metals. In fact, some jewelers offer to upgrade the head of an engagement ring to platinum to ensure the prongs securely keep the stone in place. Platinum is a premium metal to use for setting a diamond, and its strength exceeds that of gold. If you want to know more about why platinum is desirable, check out our “Diamond Setting” article. Not all of Costco’s diamonds are set in platinum. For example, smaller jewelry, such as diamond earrings are typically 14k gold. However, this is still a great metal and will make for a beautiful piece of jewelry.

Color Provides Great Value

Costco’s diamonds are rated at “I” color (mid-range, near colorless) or better. While it may be tempting to pay for the highest color grade you can afford, the value you receive for the price paid quickly diminishes after going above “I.” This is the color that I typically recommend if you want a beautiful stone without significantly increasing your budget.

Downside of Costco Diamonds

No GIA Certificate for Smaller Diamonds

While Costco claims to utilize GIA standards for all their stones, anything under 1.00 carats will not come with a GIA certification. However, most jewelry with diamonds of this size that you can buy from chain jewelry stores will also not contain a GIA certification. Therefore, while this is a trade-off of purchasing smaller diamonds from Costco, it is not much of a downside because you typically will have to buy a loose diamond if you are looking for a GIA certificate for smaller stones. Small loose diamonds will typically cost more once you factor in the cost of the setting and the jeweler’s labor. Therefore, you must weigh the benefits to determine which option is best. While I prefer to purchase loose stones as the diamond size increases, it is not always worth the cost as the size of the diamond decreases. That being said, any time I can get a GIA certificate, I want one.

No Service or Maintenance

While some chain jewelry stores offer jewelry warranty/repair services, Costco recommends finding a local jeweler. My wife loves getting her jewelry cleaned and takes full advantage of this service, which is why I chose to get her engagement ring from Jared; the in-house jeweler was a major selling point. Unfortunately, this is not something you will be able to utilize for jewelry purchased from Costco. Therefore, consider the type of jewelry you are purchasing to determine the amount of maintenance it will require. In general, earrings undergo less abuse than pieces like bracelets and rings.

Conclusion

Costco diamonds a great value. The “I” color rating and “VS2” clarity rating result in a beautiful stone at a more affordable price than diamonds with higher ratings. If your budget allows, you can choose to go higher, but most will not be disappointed with a stone of this high quality. Costco utilizes high-quality precious metals (platinum and 14k gold) to set its diamonds. Additionally, diamonds of 1.00 carat and up will come with a GIA certificate, providing the greatest confidence that the stone you purchase is rated properly. The primary downside to purchasing from Costco is the lack of jewelry service or maintenance, so you will need to find a jeweler you trust. However, Costco has great return and exchange policies, so even though they do not offer jewelry repair services, they may still provide an appealing alternative.