idazzle.com(TM)--Researching Cut, page 1

The modern round brilliant cut is fashioned into 57 or 58 separate facets, or tiny flat polished "faces" that reflect light. Diamonds reflect some light as brilliance, or white light returned to the eye. They also absorb some of it, which spreads from facet to facet inside the diamond, separating the light into spectral colors. This is known as dispersion, or fire, and when combined with brilliance, it is what gives diamonds their beauty. All of this results from cutting the diamond to a specific proportions, called make.

idazzle.com Facts:

Ancient Romans wore naturally well-formed diamond crystals as talismans. Until 1700, it was mainly men who were rulers who wore diamonds, because of the powerful connotation.

Proportion (or Make) Classes:

Class	1	2	3	4
Table	53-60%	61-64%	65-70%	>70%
Crown Angle	34-35°	32-34°	30-32°	-30°
Girdle	medium- slightly thick	thin/thick	very thin/ very thick	extremely thin/ extremely thick
Pavilion Depth	43%	42-44%	41-46%	-41/+46%
Culet	none-medium	slightly large	large	very large
Finish	very good- excellent	good	fair	poor
idazzle.com designation	"Very Good" Cut	"Good" Cut	We do not recommend diamonds in this range.

Note: Finish refers to how well the cutter has done her or his job on the details—how
the facets line up, the symmetry, etc.

Most of these details will be outlined on a diamond certificate.

The most commonly used model for the Ideal cut, or Class 1 proportions, was created by
Marcel Towlkowsky in 1919. In reality, not very many diamonds can be cut into this
model, because of limitations in the cutter’s skill, the shape of the rough diamond crystal,
and the additional weight that this model loses from the rough crystal. Many diamonds
are cut into Class 2 proportions, which are also very brilliant. It isn’t until you reach the
extremes of cutting a diamond too shallow or too deep (Class 3 or 4) that the diamond's
beauty is compromised. As in all diamond factors, try not to put too much emphasis on
only the cutting proportions. Tiny differences of 1 or 2 percent from the ideal should
be weighed against the other quality characteristics. Cutting is important, but be sure
to keep proportions and percentages in perspective.

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