How to Grasp Gem Grading

Observe the color of your gem. Gems are graded by their color, including the hue, saturation and tone. The hue refers to the actual "color," which could be red, purple or blue. The saturation of a gem refers to how strong or pastel a particular shade is. Tone refers to how light or dark the color is.

Take note of the clarity of your gem using your magnifying glass or jeweler's loupe. The clarity refers to the gem's internal purity and the type and quantity of inclusions in the gem. Inclusions are features that can be seen inside the particular gem. Sometimes, these inclusions can be seen with the naked eye and other inclusions can only be seen under magnification.

Pay attention to the carat weight of your gem. The weight of a gem is expressed in carats, and larger gemstones are less common than smaller ones. Larger, heavier gems have a higher gem grade in the carat category.

View the cut of your gem with your jeweler's loupe. Gems that have a better cut are given a higher gem grade. If the cut is done well, it will reflect light better. The cut should also be symmetrical in nature, and the facets of the gem (if present) should be well-defined and come to a single point. The surface of the gem should not exhibit scratches, dullness or pitting or it may be given a lower gem grade. Use your magnifying glass or jeweler's loupe to observe the cut of your gem in more detail.

Observe the shape of your gem. While not considered one of the 4 Cs of gem grading, the shape of the gem is very important. Gems are cut into many different shapes, including oval and marquise. Certain gems look better in certain shapes, and the appropriateness of the shape of the gem can affect the value and gem grade.