Fluorescence is the visible light some diamonds emit when they are exposed to invisible ultraviolet rays (UV). Approximately one third of diamonds emit some degree of fluorescence.
Luster refers to the way light interacts with a diamond. A diamond with a low luster grade may exhibit a hazy or oily finish, often referred to as “milky” or “greasy”. Though commonly omitted from diamond certificates, the diamond industry deems luster grade integral in establishing value.
Measured in mm: Length x Width x Height
A diamond’s table size is expressed as a percentage of its average girdle diameter.
|Serial Number Inscription:
Visible only under magnification, GIA inscribes their unique serial number onto the diamond's girdle. This gives you peace of mind knowing you will always be able to verify that this is in fact your diamond.
Black inclusions are black crystals contained within a diamond, and due to their high visibility are considered less desirable. Though not listed on most diamond certificates, nor disclosed by most retailers, it is standard practice within the diamond industry to disclose and evaluate diamonds depending on the degree and severity of black inclusions.
Symmetry refers to the arrangement and even placement of a diamond’s facets. A symmetrical facet arrangement maximizes beauty and minimizes the potential for light loss.
Diamond treatments and synthetics are increasingly being passed off as natural diamonds. Common gemological equipment can no longer detect all treatments or synthetics. Therefore only gemological institutes with advanced equipment can certify that your diamond is 100% natural and untreated.