Remember when you were a child and kept your most prized possessions in your pocket? Perhaps you hoarded your precious treasures in a little box hidden under your bed, protected from snooping siblings.
The appearance of a colored gem is a combination of many separate factors, each of which is related to, and affected by, the others. It is precisely the complexity of these intertwined relationships that has bedeviled all attempts to quantify quality.
In most gem sawing, a thin circular blade usually composed of steel, copper, or a phosphor bronze alloy impregnated along the outer edge with diamond grit and rotating at several thousand surface feet per minute literally scratches.