Precious and semi-precious stones that have been cut and polished are known as gems. There are many of types of valuable gems. Gems are evaluated under the classification scale known as the four C's. The four C's stand for color, clarity, cut, and carat. After the color classification, gems are given more distinct names such as diamonds, emeralds or rubies. The results of the four C's, combined with the its rarity and availability factors, determine the overall value of the gem.
Locate the appropriate color of the gem in the reference information. This will identify the type of gem. As different gems are close in color, the hue must match exactly for the identification to be correct. The gem's rarity and availability is detailed in the reference information.
Evaluate the gem's clarity with the jewelers loupe. Clarity refers to the level of imperfections, such as small holes or cloudiness, within the gem which prohibit the visibility of light through the gem. According to Gemsociety.org, clarity is measured as eye clean or slightly, moderately or heavily included. Eye clean refers to little to no visible imperfections while heavily included indicates a large amount of imperfections visible to the eye.
Examine the gem's cut for symmetry and light reflection. For the highest value, the gem should be perfectly symmetrical and allow natural light to reflect from its surfaces.
Use small scale to determine the gem's carat or weight. Higher amount of carats increases the gem's value. If the scale is inaccurate, a jeweler can verify the exact weight of the gem.