LaViano Jewelers – GIA Certified Quality Diamonds, New Jersey

Diamond Grade

Both the GIA (Gemological Institute of America) and the AGS (American Gemological Laboratories) have different approaches to grading the cut of a diamond, but both are based on scientifically proven systems.

GIA introduced its 'Diamond Cut Grading System' in 2005 for round brilliant diamonds. It can predict the cut grade for millions of various round brilliant diamonds. This system analyzes the diamond's face-up appearance by using computer modeling techniques and algorithms to evaluate the levels of brightness, fire and scintillation.

The AGS system uses a state-of-the-art ray tracing software to trace light traveling through a diamond. The software shows the quantity and quality of the light being returned to the beholder. AGS also considers brightness, dispersion, leakage, contrast, and weight ratio, as well as proportion, symmetry, and polish.

GIA SYSTEM	AGS SYSTEM
Cut Scale Levels Excellent, Very Good, Good, Fair and Poor	Cut Scale Levels Runs from 0 for 'Ideal Cut' to 10 for 'Poor'
Cut Grade Assessment Face-Up Appearance: most important part of the GIA’s cut grade. Brightness: refers to the “brilliance” of a stone. Fire: display of light return in strong lighting conditions. Scintillation: movement pattern of the light within the diamond as the observer or light source is moved.	Cut Grade Assessment Brightness: the “brilliance” of the stone. Dispersion: the appearance of light return that enhance the metric. Leakage: facets, which function as a “window” rather than a “mirror”, or a “non-reflector” as opposed to a “reflector”. Contrast: The light and dark patterns seen in the diamond, which produce a positive or negative optical effect.
Diamond Physical Design Weight Ratio: The appearance of the size of the diamond in relation to weight. Durability: The possibility of the diamond chipping or breaking.	Diamond Physical Design Tilt: Tilting the stone to examine its optics. Durability: The possibility of the diamond chipping or breaking. Weight Ratio: The appearance of the size of the diamond in relation to its weight. Girdle thickness: too thin or too thick is not desirable. Culet Size: must not be chipped or too large.
Diamond Craftsmanship Polish: Quality of the finish as it affects luster. Symmetry: Facet placement and alignment with corresponding facets.	Diamond Craftsmanship Polish: Quality of the finish that affect luster. Symmetry: Light return as observed in strong lighting conditions.

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