Cut          Color           Clarity           Carat Weight          The 5th C 
Carat Weight:   This measurement is equal to 1/142 of an ounce.   It does not tell you how big the diamond will look.   If a diamond is cut thick, it will have a smaller surface area than a shallow cut one.   A 1 ct. diamond with a 6.3 mm diameter will be about 15% less in value than the one that is 6.5 mm in diameter even if the color and clarity are the same.
Point:   A point is a weight measurement that is equal to 1/100 of a carat.   A 23 point diamond is .23 ct.
Crown:   The top part of the diamond.
Culet:   The point in the center on the bottom of the diamond.

Facet:   The flat polished panels on the diamond.   The Round Brilliant Cut has 57 facets and if the culet is bobbed, 58 facets.

Girdle:   The outer edge of the diamond where the crown and pavilion meet.
Pavilion:   The bottom part of the diamond.
Table Facet:   The largest facet on the top of the diamond.
Gemex Certificate:   This certificate measures only the cutting quality. 
Other certificates (eg. GIA and AGS) measure the quality of the cut by identifying angles and proportions of the diamond.   Gemex uses a brilliance scope to measure the amount of light return the diamond is capable of achieving.

Hearts and Arrows Cut:   An Ideal Cut with higher quality standards not required of the Ideal class of diamonds.   Symmetry and polish must be close to perfection.   Many diamonds will achieve an excellent polish and excellent symmetry grade on a GIA certificate or a 000 grade on an AGS certificate.   A crisp arrows design as viewed through the top of the diamonds is more difficult to achieve than the hearts design viewed through the back of the diamond.   These diamonds are considered the ultimate in brilliance for the 58 faceted round brilliant cut diamond.

Ideal Cut:   A diamond cut according to the parameters of the paper written by Marcel Tolkowsky in 1919.   In this work, he used his experience in math, diamond cutting, and the physics of light to describe the properties that created the most beautiful 58 faceted Round Brilliant Cut diamond.   These diamonds should achieve a minimum of very good polish and very good symmetry on a GIA certificate.
Premium Cut:   A diamond with a Premium Cut will have some deviations from the Ideal Cut, often restricted to a table facet that is too large.   Crown and pavilion angles must be within or very close to the standards for the Ideal Cut and the GIA certificate for a Premium Cut diamond must be VG in symmetry and polish or better.
Commercial Cut:   A diamond with significant deviations from the Ideal proportions and lacking good symmetry and polish.   Such a diamond will typically receive a grade of "good" or worse in symmetry and polish on a GIA certificate.   A cutter producing this type of diamond is more concerned about achieving a low-priced diamond than making a beautiful one.
Color:   Color refers to the body color in the diamond.   This grade does not refer to the colored flashes in the diamond.   The most common body color in diamonds is yellow.   The second most common color is brown.  Brown colors will sell for less than diamonds with a yellow body color.
Fancy Color Diamonds:   These diamonds have deep enough color to be obvious to anyone looking at it.   All of these diamonds are rare compared to white diamonds. Some of the most highly prized and most expensive colors are canary yellow, pink, and blue.   Many other colors occur, but are not often seen due to scarcity.
Clarity:   Clarity grades define the number, size, and placement of inclusion.
Inclusion (Internal Characteristic):   Any foreign body or internal characteristics found within a gemstone.   Inclusions lower the clarity grade of a diamond.

AGS-000:   0 is the highest grade assigned on the AGS grading scale.   Triple zero stands for 0 for polish, 0 for symmetry, and 0 for proportions.

Polish:   The overall condition of the facet surfaces.   The quality of the polish varies on different diamonds.   The GIA certificate carries these grades for polish; poor, fair, good, very good, and excellent.   Most GIA certified diamonds will grade "good" or "very good".
Symmetry:   The measure of how well-centered the table and culet are and the shape and alignment of the other facets.   The GIA certificate carries these grades for symmetry; poor, fair, good, very good, and excellent.   Most GIA certified diamonds will grade "good" or "very good".
GB Jewelers, Inc.
Under the Clock Tower
675 SE Marlin Avenue, Suite 1  /  PO Box 999
Warrenton, OR 97146

Latitude:  46.159033 / Longitude: -123.9055280
Store Hours: 10:00 a.m. - 6:00 p.m.
Monday - Saturday
Copyright 1974