Cut Grade - How is it determined?
The diamond is placed in a Sarin machine which measures its proportions and angels.
Depending on the result, the diamond will be given an appropriate cut grade. The
Gemmological Institute of America (GIA) introduced the cut grade on 1st January 2006 for
the Round Brilliant diamond. The options for the cut grade from the GIA are: Poor, Fair,
Good, Very Good and Excellent.
At Steven Stone, in order to maintain our high reputation for excellence and to
consistently exceed customer expectations, we only offer the top three cut grades: Good,
Very Good and Excellent.
An Excellent Cut is sometimes referred to as an Ideal Cut diamond. This means that the
diamond is perfectly proportioned. Ideal Cut grades generally apply to Round Brilliant
cut diamonds, but sometimes it is possible to obtain other shapes that adhere to this
standard. Ideal Cut diamonds are normally around 5-10% more expensive than the average
Steven Stone Tip
“The cut grade of a diamond can impact how large a diamond appears. Diamonds with a
smaller carat weight can appear larger with a better cut grade.”
Diamond Cut – Symmetry And Polish
The symmetry grade is also important when considering which diamonds to purchase. This
grade indicates how well the diamond facets are aligned. The symmetry of a diamond also
determines the amount of light returned, i.e. the sparkle. The options for the symmetry
and polish grade established by the GIA are: Poor, Fair, Good, Very Good and Excellent.
At Steven Stone we only offer the top three symmetry and polish grades of Good, Very
Good and Excellent.
The polish grade is not as important as the symmetry or cut grades. This is because it
has only minimal impact on the diamond’s light return. The polish grade refers to the
smoothness of the diamond’s facets. If the grade of polish is Poor or Fair, the diamond
may appear slightly blurred or dull. We would recommend considering polish grades of
Good or Excellent when selecting your diamond.