DIAMOND GLOSSARY

BLEMISH    
An external imperfection, in contrast to an inclusion, which is internal.

BRILLIANCE    
The richness or intensity of reflections of white light in the face-up position.

CLARITY GRADE   
The position of a diamond's clarity grade falls on a GIA scale that ranges from flawless down to I3. The lack of or amount of inclusions and blemishes, along with size and location, designates the clarity grade.
 
CLOUD   
An inclusion that is generally made up of a multitude of tiny feathers or crystals. Sometimes very slight and sometimes making the diamond hazy.
 
COLOR   
A large part of the value of a diamond is determined by its color. Each diamond falls into a color grade set by the GIA standard color grading scale which starts at "D" and ends at "Z" before entering the fancy color ranges. “D-F” is considered colorless; “G-J” is considered near colorless and “K” and below is light yellow and darker.
 
CROWN  
The top part of a diamond, from the girdle to the table.
 
CULET  
A protective facet at the convergence of all the pavilion (bottom) facets. When the cutter chooses not to polish a culet on the diamond, it may still be referred to as a pointed culet. A large culet is a negative characteristic since it allows unnecessary escape of light.
 
DISPERSION   
Diamond and other gemstones have the ability to refract
(bend) light displaying the spectral colors of white light.
 
DEPTH   
The depth of a diamond is usually expressed as a percentage. A measurement between the table and the culet is taken and divided by the narrowest diameter.
 
DIAMETER  
The width of the diamond, measured around the girdle.
 
DISPERSION  
The result of white light splitting into all the colors of the rainbow.
 
DOUBLE REFRACTION   
Some gemstones due to crystalline structure refract (bend) the entering light in two different directions. Synthetic moissanite, the popular diamond imitation, is doubly refractive. Diamond is singly refractive.

EYE-CLEAN CLARITY   
A term meaning no flaws are visible to the unaided eye when viewed from 12 inches away, with the diamond face up.
 
FACE UP  
The diamond viewed from the top of the stone.
 
FACET  
The flat, polished surfaces on the diamond. All Diamond Ideals diamonds have 57 facets.
 
FIRE  
When moved, these are flashes of color reflected from within a diamond, resulting from dispersion. Just like a prism, white light entering a diamond separates into all the colors of the rainbow.
 
FLAW  
Any external or internal imperfection in a diamond.
 
FLUORESCENCE  
The luminescence exhibited in certain diamonds when exposed to ultraviolet light or strong sunlight. Fluorescence is most commonly blue in color, but can also be a variety of other colors.
 
GEMOLOGICAL INSTITUTE OF AMERICA   
A nonprofit organization for the purposes of education in diamond and gem identification. They operate Gem Trade Laboratories and Gem Instruments Corporation.
 
GIRDLE  
The narrow band encircling the widest part of a diamond. It may be faceted or non-faceted. All Diamond Ideals diamonds have the AGS certificate number laser inscribed on the girdle for your protection.
 
INCLUSION  
An impurity within a diamond. Inclusions may or may not be visible with the unaided eye. Fewer inclusions ensure a finer clarity grade.
 
PAVILION  
The bottom part of a diamond, from below the girdle to the tip of the culet.
 
POLISH  
The smooth, shiny finish on the facets of a diamond. Ideal polish is critical for maximum diamond brilliance. Diamond Ideals sells only diamonds with Ideal polish, the highest grade given by AGS Labs.
 
PROPORTIONS  
The cutting quality relative to the depth percentage, table percentage, girdle percentage, symmetry and crown and pavilion angle. Proportions influence light refraction and reflection within the diamond. Diamond Ideals sells only diamonds with Ideal proportions, the highest grade given by AGS Labs.
 
RAPAPORT DIAMOND REPORT   
A diamond price index publication by Martin Rapaport. The index is also available on the Internet with a paid subscription.
 
SCINTILLATION   
Flashes of reflected light from a diamond when it moves. Commonly referred to as sparkle. It is the movement of the reflections (brilliance) and dispersion (spectral colors), as the diamond (or other gemstone) is rotated or tilted before the viewer's eyes.
 
SYMMETRY  
The overall uniformity of a stone's cut, which can range from poor to Ideal. The symmetrical alignment of facets makes for a more stunning diamond. Facets on a diamond should be a mirror image of each of their opposites. The kite-shaped mains on both the crown and pavilion should all look the same. If the culet or table of the diamond is off center, this will have a negative affect on the symmetry.
 
TABLE  
The largest, flat facet on the top of a diamond.