How To Examine A Diamond

The traditional '4 C's' determine the value of the diamond. The '4 C's' are clarity, color, cut and carat weight. Cut will be subdivided into the 'finish' and 'proportions'. As far as carat weight is concerned diamonds logarithmically increase in value. This means that a half-carat diamond will have a higher value than two one-quarter carat diamonds.

Likewise, a 1 ct. diamond will have a significantly higher value than two one-half carat diamonds. The reason for this is due to the fact that the larger the diamond is, the harder and rarer it is to find the original crystal from which the diamond is cut.

How to properly view a diamond internally When contemplating purchasing a diamond you should ask the jeweler for a 10X corrected eye loupe in order to properly examine the diamond. A stereoscopic binocular microscope with dark field illumination set at 10X is better still but not essential.

Dark field illumination simply means that the diamond is held against a black background in the microscope and light enters the diamond from the sides and therefore all internal inclusions are easily visible. The circular well within the microscope is lit and the diamond is held at the top of the well. In this manner a great majority of the light enters the sides of the diamond and the clearest internal view of the diamond is obtained. Bring the eye loupe right up to your eye in one hand and hold the diamond ring or the loose diamond in a tweezer in the other hand. At this stage bring the diamond to a distance of approx. one inch away from the eye loupe and focus until the entire interior of the diamond is in clear view.

Try to locate any surface blemishes or internal inclusions within the diamond. You may have difficulty at the beginning so ask your jeweler to help you spot any inclusions present. Be sure that the loupe is 10X since clarity standards and grades are determined under 10X power.
If you view the diamond from the side you will most likely notice a somewhat thick whitish line midway from the girdle to the point of the diamond.

THIS LINE IS SIMPLY THE REFLECTION OF THE GIRDLE IN THE PAVILION FACETS. THE PAVILION ACTS AS AN INTERNAL MIRROR AND IS SIMPLY REFLECTING THE GIRDLE. THIS IS A NORMAL TYPE OF REFLECTION AND THIS REFLECTION SHOULD BE THERE.

Do not touch a loose diamond with your hands as this will leave a film and grease layer over the diamond. To pick up a loose diamond with a tweezer, place the diamond table down on a flat surface and position the diamond between the two arms at the end of the tweezers and grasp the diamond with the tweezers from the girdle edge at each side.

Be sure that you have access to good lighting. The best lighting for viewing diamonds is a combination of white fluorescent light and incandescent light. Strong halogen quartz lights tend to give diamonds a slightly yellowish tinge. After you have the diamond focused under the loupe look at the diamond from an angle instead of straight down in order that plenty of light is available. Look through the table or large flat surface on the top of the diamond in order to view the interior of the diamond. Observe the diamond from the sides in order to view the girdle. All inclusions should be visible from the table. Turning the diamond upside down and looking at the bottom or pavilion of the diamond usually results in viewing reflections off the pavilion surface.

Diamonds are carefully assigned a clarity grade by a trained observer or gemologist under a 10X magnification. Clarity refers to the relative degree to which a diamond is free from inclusions and blemishes. The clarity grade assigned has an effect on the diamond's value in the present market. Perfect or flawless diamonds are extremely rare. The effect of very minor inclusions and blemishes on beauty is infinitesimal. On the other hand, a heavily included diamond will not allow the light the freedom of traversing the diamond without being blocked, distorted or deflected and this will ultimately effect the overall brilliancy of the diamond. A diamond of lower clarity may give more satisfaction to a customer for his dollar than a smaller high clarity grade diamond.