Diamond, Engagement Ring, and Jewelry Buying Guides
Diamond Cut
A diamond's cut is considered to be the most
important of the four Cs. It is important to understand how a diamond's
proportions and the relationship between them effects its brilliance,
fire, and scintillation.
Diamond Guide
Diamond Cut
Diamond Color
Diamond Clarity
Carat Weight
Diamond Certification
Diamond Care
IDEAL CUT DIAMOND
Cut, more than any other quality aspect, gives the diamond its sparkle.
A diamond gets its brilliance and scintillation by cutting and
polishing the diamond facets to allow the maximum amount of light that
enters through its top to be reflected and dispersed back. When all the
angles are correct, the light that enters is dispersed back through the
diamonds top facets.
INFERIOR CUT DIAMONDS
Most
diamonds are "spread" in their cutting to retain maximum weight from
the original rough. A heavier diamond will result, but a dramatic
sacrifice of potential fire and brilliance. The width and depth have
the greatest effect on how light travels within the diamond, and how it
exits in the form of brilliance.
Shallow Cut Diamonds
When a diamond is cut too shallow, light leaks out of the bottom,
brilliance is lost and the diamond appears watery, glassy and dark. A
diamond with these characteristics is referred to as a "fisheye".
Deep Cut Diamonds
When a diamond is cut too deep, light leaks out of the sides,
brilliance is lost and the center of the diamond will appear to be
dark. A diamond with these characteristics is referred to as a
"nailhead".
A diamond cutter spends years mastering his craft, learning how best to
cut a rough diamond to achieve the ultimate cut with the fewest
imperfections and the least loss of carat weight. The better the cut,
the more valuable the diamond.
DIAMOND PROPORTIONS
Experts express differing opinions on the best table size (the diameter
of the largest facet on the top of the stone) and the best depth for a
diamond, because these factors alone are not sufficient to accurately
judge its cut.
Other factors - crown angle, girdle thickness, pavilion
depth-percentage (the ratio of depth to girdle diameter), culet size,
polish and symmetry - also play a role in judging a diamond's overall
cut quality.
A diamond's cut is
graded by several measurements. Its depth percentage, a measurement of
the height vs. the width of the stone and its table percentage, a
measurement of the diameter of the top facet of the stone vs. the
stone's average width, are two key factors in determining the quality
of a diamond's cut. These percentages are detailed on the GIA Gem Trade
Laboratory Diamond Grading Report that accompanies every IcedTime
loose diamond.
Polish & Symmetry
Although
polish and symmetry are graded under 10X magnification they can both
have an affect on the overall appearance of a diamond. Polish refers to
the quality of the diamond's surface and includes such features as
nicks, polish lines and abrasions. Symmetry refers to the exactness of
the shape and alignment of the facets.
Some of the symmetry characteristics of round diamonds are listed below:
Off-center culet
Facets not properly pointed
Misshapen facets
Crown and pavilion misalignment
Off-center table
Table and girdle not parallel
The polish and symmetry grades are listed in each diamond detail page
and within the AGSL or GIA diamond grading report. AGSL grades polish
and symmetry as ideal (ID), excellent (EX), very good (VG), or good
(G). GIA graded diamonds will have polish and symmetry grades of
excellent (EX), very good (VG), or good (G).
IcedTime does not carry lower quality diamonds with polish and symmetry grades of fair (F) or poor (P).
