Αποτελέσματα Αναζήτησης
estimating a GIA Cut Grade for round brilliant diamonds with crown angles between 22.0 and 40.0 degrees, pavilion angles between 38.8 and 43.0 degrees, and table sizes
The GIA Cut Grading System for standard round brilliant cut diamonds (D to Z colors only, 0.15 carat and larger) was launched on GIA Laboratory grading reports in January 2006. Standard round brilliant diamonds are evaluated for one of five possible cut grades: Excellent, Very Good, Good, Fair, and Poor.
GIA Cut Grade Estimation Tables for Standard Round Brilliant Cut Diamond Explains how to locate a particular proportion combination, and determine whether it is close to a boundary in the cut grading system.
In fact, it is estimated that 90% of the round diamonds are cut to dismal proportions by choice. As a consumer, here’s your bottom line when selecting a round diamond for light performance. There’s ABSOLUTELY NO wriggle room when it comes to proportions.
assumption of the ideal proportions of the brilliant cutting for diamond to be close to the following: Top angle, 35°; back angle, 41°”2. In the early 1900s, cutting houses in London and Europe, who were polishing diamonds for the relatively large and burgeoning American market, were cutting to the lower
worked to establish the ideal angles and proportions to cut the facets of the Standard Round Brilliant (SRB) diamond in order to produce the ‘Ideal’ gem. This paper reviews
The new GIA diamond cut grading system aims to show that you can get "ideal" brilliance from a set of proportions that have not traditionally been considered to be "ideal". The GIA intends to change the use of the phrase "ideal cut" by introducing a grading system which allows for a much wider range of proportions and measurements.
