COLOR GRADING-Selective Absorption - causes color of diamond.
-HUE - Basic spectural sensations of color.
-TONE - Lightness to Darkness of a hue. (ranges from very light to very dark).
-SATURATION - The strength of a HUE (color) ranging from vivid to dull.
-FLOURESCENCE- Lowe value, The ability of a gemstone to glow.
Master Stone - Every master stone represent the best color in that range. F color grade master stone represents the Best F color grade, the same goes on for H and so on.