2010年7月28日星期三

Solitaire Diamond Rings: Certification and Grading

GIA established the standards and methods for a diamond evaluation, which all labs now follow. If you find the solitaire diamond rings are diamond that isn’t accompanied by a grading report, ask your seller to send it to a reputable lab to have it evaluated. Some points to bear in mind while buying your favorite diamond ring are discussed below:MeasurementsThe measurements of a diamond are primarily used for identification purposes, since no two diamonds are exactly alike in weight, quality and measurements together. For fancy shape solitaire diamond rings like the princess, marquise or pear shapes, the overall length-to-width ratio is important because certain proportions are more appealing to the eye. To compute the length-to-width ratio of a fancy-shaped diamond (;fancy shape; means anything other than round brilliant), take the length of the diamond and divide by the width. Example: A marquise that measures 8 mm x 5 mm has a 1.6:1 ratio.A Diamond Grading Report is a report or certificate issued by an independent Gemological Laboratory, which states that a diamond (usually over 1 carat) has been examined using various gemological instruments, compared to similar master diamonds, and has been found to contain the characteristics listed in the grading report. The Gemological Institute of America, GIA, is the largest and most well known laboratory in the world and as such, a diamond accompanied by a GIA report will cost more, although the diamond may not be worth more.