How to Grade a Red Ruby

Gem traders and jewelers base the value of rubies on a grading scale that assesses various characteristics of the gem. The grading scale, which was developed by the Gem and Jewelry Institute of Thailand, determines the ruby's worth, what it should be purchased for and how much traders and jewelers should sell it to consumers for. Understanding how to grade a red ruby can help you determine whether you are getting a good deal on your gemstone or are being asked to pay too high a price for it.

Instructions:

1. 1. Evaluate the ruby's red color. The ruby grading system evaluates the color based on different color notations, which include dark red, deep red, vivid red, strong red, pinkish red and purplish red. The dark red rubies are graded the most valuable, while the purplish red rubies are considered less valuable on the grading scale. According to the Canadian Institute of Gemology, a ruby's color determines at least 50 percent of its market value price.
   2. Look at the hue of the ruby. The hue refers to dominant and secondary colors. As an example, a pinkish red ruby has red as the primary color and pink as the secondary color.
   3. Assess the ruby's saturation by noticing the light and dark pigments. A higher-grade ruby has a more intense saturation of color than weaker tones.
   4. Inspect the gemstone for clarity. Clarity refers to the amount of inclusions in the stone. An excellent clarity score means that the ruby has minute inclusions, a fine score indicates minor inclusions, a score of very good means there are noticeable inclusions, good is the grade for moderate inclusions and fair means there are significant inclusions in the stone. Use a magnifying glass to get a close look at the ruby's inclusions.
   5. Inspect the brilliance of the ruby, meaning how much it twinkles. A high-grade faceted gem has a lot of brilliance, where a poorly-faceted gem appears more dull.
   6. Look at the ruby's cut. The face-up evaluation method means that when you look down at a ruby the opposite sides of the stone should look to be the exact same size. This enhances the ruby's aesthetic appeal. Examine the profile of the stone. Look for a centered cutlet and a straight girdle.
   7. Weight the ruby with a small scale. A ruby with a higher carat weight is more valuable and graded more highly than smaller rubies, which are easier to find.

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