Different Grades of Gemstones

We have summarized and evaluated the following for grading purpose:

The value of a gem is mainly based on its color. Here are the fundamentals you require:

Color of the Gems

There are 3 main colors like yellow, blue, red, and 3 secondary colors, which are the result of blending basic colors like green, orange and purple.

There are different kinds of colors available, blue-violet, yellow-green, red-orange, which are a basic color mixed with a secondary color.

When any color is mixed with black, white or grey, we require the definitions of tints, imbues and saturations.

Saturation 

Saturation implies the quality of perception of gray of the same lightness. All grays generally have zero saturation. According to theory, complete saturation entails that there is 0% gray in a color.

Imbue 

Imbue is color believed to be green, yellow, and purple etc, implying gray, black and white have no imbue.

Tint

A color blended with white is a tint. A tint is less saturated and lighter than a color without the addition of the white.

Tone and Color Grade

Color grade describes the strength of the main color with respect other colors visible in the stone. A 100% color grade of blue for instance would entail that there are no other colors such as violet or purple visible in the stone.

Grade of Color

Poor-9-10

Fair-7-8

Good- 5-6

Very Good-3-4

Excellent- 1-2

The scanning of color will generally break down the 3 perceived colors that total 100% color grade, but such a stone will never be found.

Usually the rule that applies is: the purer the color the better is the grade. But grade is not related with tone.

Tone of Color       

Any grade of color should be blended with the tone.

A colored stone can also be black (dark 95) or white (light 5) with just some hint of color of the lucky gemstones.

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