Cut

The cut not only refers to the diamond shape but also to its proportions and finish. It is the only way a diamond value is influenced by hand; the other 3 are determined by nature.

A well cut diamond can make light perform in breath-taking ways, which results in magnificence of the diamond itself, displaying 3 important attributes:

Brilliance – the total light reflected from a diamond

Fire – the dispersion of light into the colours of the spectrum

Scintillation – the sparkle when a diamond is moved

The factors which determine a diamonds overall cut is table size, crown angle and pavilion as well as the thickness of the girdle.

Ideal or Excellent cut grade:

In 1919, Marcel Tolkowsky developed a mathematical formula for cutting diamonds to precise angles and proportions to gain the best reflection and refraction of light, creating the optimum balance, sparkle and fire of a diamond. Over the years those proportions changed and gradually have become the modern ‘round brilliant cut’. Today the term ideal or excellent cut refers to the attempt to cut a round diamond into the best proportions to achieve maximum brilliance. There are many different combinations of proportions that succeed equally well in achieving that deal of excellence. One of the main cuts is hearts and arrows:

Hearts and arrows:

These are mostly round diamonds with superior cutting quality. Hearts and arrows are highly symmetrical, reflected light patterns which visually demonstrate the optimal symmetry of an excellent cut diamond. The name refers to 2 separate light patterns seen when a diamond is viewed through the pavilion (face down) or the table (face up).

The reflective qualities of a diamond cut:

When a diamond is perfectly cut, light rays from all sides are bent towards the centre of the stone and reflected back though the top in a rainbow of light.

If a diamond is not perfectly cut, light will escape through the base or sides of a diamond as seen in the images below: