Understanding Diamonds

What you should know

At Simons, we know the diamond search can be daunting and confusing. And it’s normal to be a little nervous or overwhelmed. It’s an important decision.

We’re here to help you find the right diamond that fits your specifications and has the kind of beauty your loved one will enjoy for a lifetime.

Our friendly staff does not work on commission. They understand diamonds and are here to help. We can procure diamonds of almost any quality and size. We’ll work with you to find a quality diamond that fits your budget. And we pride ourselves on making the selection process stress-free.

Check out the GIA content below to better understand the diamond basics. In no time, you’ll have a grasp of what goes into diamond shopping.

How to choose a diamond – GIA grading System

The 4Cs


Cut is the most important aspect of a diamond’s grade in determining overall beauty. A high cut grade indicates that a diamond has a lot of brilliance or sparkle. When it is cut with the ideal proportions for its shape, it will reflect more light, resulting in higher levels of fire and brilliance.

Diamonds cut with poor proportions will allow light to escape out the bottom and sides, resulting in a dull, dark appearance. In short, a well cut diamond sparkles a lot because it reflects and refracts light better than one not cut as well.



White diamonds are not all colorless. The spectrum ranges from light yellow to totally colorless. A lettering system from D to Z is used to identify the amount of color present in each diamond, with D awarded only to rare, totally colorless diamonds. A colorless diamond can be graded D, E or F; near colorless, G, H, I or J.

A white diamond’s beauty and value increase the more colorless it is. Colored diamonds are also available, such as pink, blue, chocolate or bright yellow, but are rated on a different scale than white diamonds.



Natural diamonds are formed by tremendous heat and pressure deep within the earth. This process can result in internal “inclusions” and external “blemishes.” A diamond’s clarity grade is determined by the number, size, nature, position and relief, or color, of these characteristics. In higher quality diamonds, these imperfections are not visible to the naked eye.

No diamond is perfect, but the closer it comes, the higher its value. A “flawless” diamond is rare. Minor inclusions seldom affect a diamond’s beauty, although they can affect value.


Carat Weight

Refers to the weight of a diamond. Larger diamonds are more scarce, and therefore more valuable.

However, two diamonds with the same carat weight can vary greatly in value, depending on the color, clarity and most importantly, the cut. A half-carat diamond with high color and clarity ratings may cost more than a three-quarter carat diamond with lower color and clarity ratings, but identical cut. It’s simply a matter of deciding what factors matter most to you, then finding the best combination of size, color and clarity to suit your budget.


The Shape

Each shape has characteristics that determine the quality of a specific stone. However, these shapes can have an impact on how the ring looks and feels. Most center diamonds come in one of the following shapes:


  1. Round Brilliant — the most popular; cut for maximum brilliance.
  2. Princess Cut — A “fancy-cut” diamond; with pointed corners often in a square shape.
  3. Oval — a modified brilliant-cut with similar fire; elongated shape creates the illusion of greater size.
  4. Cushion — a square or rectangular cut with rounded corners, much like a pillow; many facets give wonderful brilliance.
  5. Asscher Cut — an elegant square shape with blocked corners that make diamonds appear octagonal.
  6. Emerald — rectangular with parallel facets and blocked corners; produces a hall-of-mirrors effect.
  7. Marquise — an elongated shape with tapering points at both ends; flatters the finger.
  8. Pear — teardrop-shaped, with a great deal of sparkle.
  9. Radiant Cut — a combination of the emerald cut and the sparkle of the round brilliant; typically with blocked corners.
  10. Heart — a sentimental cut that is sometimes hard to find.

All 4Cs information: Copyright © GIA. All rights reserved. Special thanks to the GIA for use of these materials. This information is not intended to replace the services of a trained jeweler or gemologist regarding analysis or appraisal of any particular gem or jewelry item. Come speak with one of our staff.