Cut
Refers to the angles and proportions of a diamond.
Cut refers to the angles and proportions a skilled craftsman creates in transforming a rough diamond into a polished one. Based on scientific formulas, a well-cut diamond will internally reflect light from one mirror-like facet to another and disperse and reflect it through the top of the stone. This results in a display of brilliance.
Diamonds that are cut too deep or too shallow tend to lose or leak light through the side or bottom, resulting in less brilliance and value.
Cut is the only one
of the 4Cs that is influenced by the human hand. The rest (color, clarity,
carat) are created naturally
as diamonds form in the earth.
Diamond cutting requires
great skill and training. The cutter must polish tiny surfaces —known
as facets—onto the rough diamond. This process is what creates the crown,
culet, table, girdle and pavilion of the diamond.
The facets, when arranged in precise proportions, will maximize brilliance and sparkle. To cut a diamond perfectly, a craftsman will often need to cut away more than 50% of the rough stone.
Cutting Style
Cut and cutting style
work in harmony to create a diamond’s brilliance. Cutting style is categorized
into three basic types:
brilliant-cut, step-cut and mixed-cut. The difference among these three
types is the facetting arrangement of each style.
Brilliant-cuts reflect the most light and are considered to have the greatest brilliance of all cutting styles.
Step-cuts have rows of facets that resemble the steps of a staircase. The emerald and baguette are examples of this cutting style.
Mixed-cuts have both step and brilliant-cut facets. An example of a mixed-cut is the Princess.
Ideal Cut
The ideal cut of a round brilliant diamond is open to interpretation within the industry. Ideally, you want a table percentage that provides the best balance of brilliance (reflected light) and dispersion/fire (reflected hues), and a depth percentage that allows for the highest yield of return light. Some acceptable numbers are:
TABLE 53–60%
CROWN 34–35%
GIRDLE medium to slightly thick
DEPTH 60–62%
PAVILION 43%
CULET none to medium
FINISH very good to excellent