GSI Certification: What You Should Know Before Purchasing a Diamond

By Michael Fried

Scared of getting ripped off? Don’t want to waste your money? Confused by all the choices? Contact us.

Visit our Top Recommended Vendors

Bottom Line Recommendation:

Top Recommended Vendors
We do not recommend buying a diamond with a GSI certificate. We’ve found that GSI grading is not only looser than the gold standards (GIA and AGS labs), but weaker than the next level down (IGI and HRD) as well. Unfortunately, GSI does not even carry the consistency to purchase a lower graded diamond and adjust the value accordingly. You should only buy diamonds with an GIA or AGS certificate from a reputable vendor like Blue Nile or James Allen. You will actually know what you’re getting from a value perspective and you can compare apples to apples. Retailers don’t use inaccurate certificates like GSI in order to give the consumer a better deal; they do it to make more money off of those consumers.

History of GSI

Gemological Science International (GSI) is a recently established for-profit organization. This commercial laboratory has been around for a few years, not decades like other lab organizations. It’s the only major gemological lab to be founded in the 21st century. Unfortunately, they didn’t come to the industry with fresh ideas or innovative technology. They built their business by appealing to big retail chains in the United States, like Jared The Galleria of Jewelry, Kay and Zales. GSI primarily grades diamonds for large chain stores, and their service is usually speedy.

With locations all over the world, GSI provides gemstone identification as well as grading and appraisal services in the fine jewelry industry. Overall, like EGL and IGI certifications, GSI is consistently looser in their grading than GIA.

GSI Diamond Grading Report

A GSI report shows the evaluation of a gemstone based on its structure and quality. The scales and measurements are intended to provide a reference point when purchasing.

Grading Results and Scales

The 4 C’s (Cut, Color, Clarity and Carat) of a diamond represent its four main components. Each C is graded on a scale to help determine the quality and value of a diamond.

IDX report recreation

Cut

Diamond Cut refers to the quality of a diamond’s proportions, angles and symmetrical facets.

GSI designates Cut grade on the following scale:

  • Ideal
  • Excellent
  • Very Good
  • Good
  • Fair
  • Poor

Color

A diamond is evaluated for how white or colorless it is. The GSI grades diamonds from D to Z: D being the most colorless and Z containing noticeable brown or yellow tinting. It is difficult for the naked eye to distinguish two diamonds of adjacent color grades, especially ones graded by the GSI. It is best to seek a more reliable certificate, like one from the GIA or AGS, and ensure that the diamond looks colorless to the naked eye.

Clarity

Clarity grade determines how clean a diamond is from inclusions and blemishes. We recommend purchasing a diamond that is eye clean, so inclusions do not interfere with natural light reflection.

Carat

Carat is measured in standard fashion across all grading entities, as it is based on weight. A 2 Carat Diamond equals 400 milligrams or 0.4 grams—weighing approximately the same as a quarter of a raisin. A GSI report will disclose the Carat of a diamond, though Cut quality remains the most important of the 4 C’s.

Proportions

A diamond’s proportions can help determine the quality of the Cut, although it is difficult for someone without diamond expertise to make a judgment based on the measurements provided in a GSI report.

Graph of diamond proportions

Additional Grading Information

Other details, like symmetry and polish, will also appear on a GSI certification. While these aspects contribute to the beauty of a diamond, the more important factors are the 4 C’s.

How GSI Certification Impacts Cost

Because GSI primarily works with large chain jewelers like Zales and Jared The Galleria of Jewelry, it is difficult to assess how truly objective they are in grading diamonds. While a diamond graded by the GSI will be less expensive than a diamond who achieves the same grades on a GIA scale, the GSI diamond will be worth much less. The inconsistency and looseness in grading make a GSI certified diamond a risky purchase at best.

Advantages of GSI Certification

  • Provides an indication that you should look for another diamond (one certified by the GIA or AGS)
  • Offers a grading discount to diamond vendors
  • Provides fast grading services to diamond vendors

Disadvantages of GSI Certification

  • Very loose grading
  • Lacks quality and consistency in grading
  • Does not allow you to compare two diamonds due to weak grading
  • Unique Reports and Additional Services

The GSI provides full reports for their diamonds along with:

  • IDX and MDX (smaller versions of a full certificate)
  • Trade Consultation Report
  • Hearts and Arrows Report
  • Light Performance PSX Report
  • Metal Engraving
  • Laser Inscription
  • Virtual Vault (a consumer security service)

Overall, we do not recommend buying a diamond that has a GSI certificate. We strongly encourage only buying diamonds that have a GIA or AGS certificate. By pursuing a more reliable certificate, you actually know what you are purchasing and you can compare diamonds fairly. Retailers don’t use inaccurate certificates like GSI in order to give the consumer a better deal; they do it to make more money off of those consumers.

If you have questions about lab certifications or want assistance in ensuring you purchase only a high-quality diamond, please don’t hesitate to contact us.

About the author
Mike learned the diamond business from the ground-up at Leo Schachter Diamonds - one of the world's top diamond manufacturers. He has been recognized as a diamond industry expert by Time, PeopleMoney, The Daily Mirror, NerdWallet, The Times Herald, Yahoo Finance Australia, The Art of Charm, The Washington Diplomat, The Next Web, and more. See more
Top Recommended Vendors
Blue Nile Blue Nile is the largest and most well known internet jewelry seller. They have the industry-leading largest available exclusive online inventory. Their high quality images are catching up to James Allens' and their prices are amazing. Exclusive to us for the 2018 Christmas shopping season - Pick Up a single-use Blue Nile Coupon Here for $100 off!
What we love about them:
  • No questions asked returns within 30 days of shipment. Blue Nile will send you a paid shipping label to return the ring.
  • Lifetime Warranty
  • Free Shipping
  • Free prong tightening, repolishing, rhodium plating and cleaning every 6 months
  • Provide insurance appraisal
  • One free resizing within the first year of purchase
  • High quality images of about half of their diamonds
  • 24/7 Customer Service
  • 100% credit towards future upgrades (must be at least double in value)
  • Best in class fulfillment

James Allen James Allen is the leader in online diamond sales. Their imaging technology is at the point where it's almost the same as inspecting a diamond with a jeweler's loupe. Their customer experience is best in class, and they have recently upgraded their non-engagement jewelry inventory as well. Take advantage of their ongoing 25% Off Holiday Sale.
What we love about them:
  • No questions asked returns within 30 days of shipment. James Allen will send you a paid shipping label to return the ring.
  • Lifetime Warranty
  • Free International Shipping
  • Free prong tightening, repolishing, rhodium plating and cleaning every 6 months
  • Provide insurance appraisals
  • One free resizing within 60 days of purchase
  • Free ring inscriptions
  • Best-in-class high quality imagery of all diamonds in stock
  • 24/7 Customer Service
  • Best-in-class packaging

Still afraid of getting ripped off?

Before you buy a diamond, get personal buying advice from industry veterans. We'll help you get the best diamond for the money.

Ask your diamond purchase question here

  • This field is for validation purposes and should be left unchanged.

DISCLAIMER: We don't use your email for marketing. Period.

Why we are doing this for free?

Click for Diamond Purchase Advice 100% Free

Ask your diamond purchase question here

We are a team of diamond experts who will teach you to identify scams and avoid spending money on features you can't see. Tell us as much information as possible to help us help you (ie, budget, preferences, etc)

  • This field is for validation purposes and should be left unchanged.

Cancel

DISCLAIMER: We don't use your email for marketing. Period.

Please enter your email address to receive your personal code:

Here is your coupon code: GFDSF3GF