Similar to diamonds, there are the 4C + 1 to determine your gemstones value.
4. Carat Weight
Color is one of the prime aspects what determines the beauty of a gemstone. In the case of most stones, it is not diagnostic in identification, because many have the same color and numerous stones occur in many colors. All gems have a preferred color or a relatively small range of preferred colors. The more the color varies from this range -- lighter or darker, more vivid or less -- the less valuable the stone. Color is composed of three dimensions: hue, tone, and saturation.
Cutting gemstones is a process of turning rough, unpolished stones into gemstones as we know them, so they can be used in jewelry. Cutting gives the stones a specific shape and enables the true color and brilliance of the gem to emerge. Gem cutters generally need over two years of experience to be considered professionals, and it takes many factors to decide which cut would work best for a given rough stone to best hide its imperfections and to bring out its best qualities. Below are the many cuts and shapes that a cutter would be considering from in order to pass on the best value to his customer.
A factor in the evaluation of most gemstones is their transparency. Inclusion of foreign matter in the interior of the crystal affect the transparency or clarify. It is natural that one gem has inclusion because it comes from natural. In trading term, we only use 10x to zoom in and determine the gemstone clarity.
The carat (ct) is a unit of mass equal to 200 mg. The carat is divisible into one hundred points of two milligrams each. Two different gemstones may have the same dimensions but different weights. This is due to the specific gravity or density of the gem mineral. Up to a certain point, the larger a stone is, the more rare it is and the higher the price it will command. For stones that commonly occur in larger sizes, the value may decrease if the gem reaches a size that makes it impractical for jewelry use.
The various combinations of color, clarity, cut and carat weight are primary factors in determining the value of a gemstone. Some other factors that impact rarity are the abundance of a particular gem type. Several gemstones are more abundant and are more easily accessible than others. Many other gems are found in remote locations, which makes mining virtually impossible. The economic and political environments of the region where the gemstones are located may also limit the accessibility of some gems. Modern technology allows for the creation of many gems from mineral elements for greater affordability.