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GIA Facetware® Cut Estimator

GIA has produced not only a means of assessing a diamond's overall cut quality, but also a way to predict it accurately and consistently. GIA's database contains cut grade results for over 38.5 million proportion combinations. Leading optical measuring devices that include the GIA Facetware® Cut Estimator Database are now available from their manufacturers. And GIA Facetware®, a free online version of this database, can be accessed here:

Other supporting products include a simplified paper version of the database, the GIA Facetware® Quick Reference Guide; the GIA DiamondDock™ Viewing Environment; and the GIA Multi-Purpose Gemological Reticle.

GIA Facetware® Look-Up Tables

You can now view the cut grade results from the GIA Facetware® Database in table format, which allows you to visualize how cut grades change through proportion space. This format may be especially helpful to manufacturers who would like to know how to change proportion values to attain better GIA cut grades.

Currently, the tables allow you to vary only the table size, crown angle and pavilion angle only. By choosing a value for one of these proportions from one of the pull-down menus, you will be directed to the appropriate cut grade look-up table in which your chosen value is the constant, and differences in the other two proportions are shown in the x- and y-axis. To access GIA Facetware® Look-up Tables, please click here.

GIA Cut Grading System Charts and Booklets

In an effort to help you understand the GIA Cut Grading System more fully, and to make the best use of it in your business, we provide these informative charts and booklets that summarize the system, and discuss each aspect of it.

"How the Laboratory Describes Round Unmodified Brilliant Cut Diamonds" — learn the difference between the old European cut, the circular brilliant cut, and the round brilliant cut and which cuts are assigned a GIA Cut Grade.

White paper, 6 pages.

"Estimating a Cut Grade Using the GIA Diamond Cut Grading System" — explains the system, gives definitions, and displays the proportions listed on a GIA Diamond Grading report. It shows twenty-five example images of round brilliants — five in each of the five grade categories — and gives their proportion combination, values for additional parameters, and a short caption about why that diamond belongs in that grade category.

Large format chart, 32"h x 42"w (81 cm x 107 cm).

Chart in booklet form, 10 pages.

"Finish, Culet Size and Girdle Thickness: Categories of the GIA Diamond Cut Grading System" — explains and provides visual illustrations of the additional parameters that may limit the cut grade derived from the proportion combination: polish and symmetry, culet size, girdle minimum and maximum, and painting and digging out.

Large format chart, 32"w x 42"w (81 cm x 107 cm).

Chart in booklet form, 12 pages.

"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. It also discusses how to use Facetware online to obtain a more accurate estimate of a cut grade.

Full-color, 8 page booklet.

Download a cover letter from Tom Moses, senior vice president, GIA Laboratory and Research, for additional information about these charts and booklets and how to use them.

GIA DiamondDock™ Viewing Environment

The GIA DiamondDock™ (patent pending) is a lighting and viewing booth developed by GIA researchers to provide a balanced and consistent environment within which to assess and display the cut appearance and quality of round brilliant diamonds. The GIA DiamondDock™ creates standardized balanced lighting by combining diffused fluorescent and LED light.

An indispensable tool for assessing and displaying the cut appearance and quality of round brilliant diamonds, each unit is fully calibrated to provide precise and correctly balanced lighting. Special diamond trays are included for ease of viewing diamonds and comparing sets of diamonds.

To purchase, click here.

GIA Multi-Purpose Gemological Reticle

The GIA Gemological Reticle is an ideal tool for measuring diamond proportions, such as table size, crown angle, pavilion angle, and total depth. When used with most gemological microscopes, the GIA Gemological Reticle enables you to obtain the necessary proportion values that can be used with the GIA Facetware® Cut Estimator and the GIA Facetware® Quick Reference Guide to obtain an estimated cut grade. A detailed booklet providing instructions on measuring is also included.

To purchase, click here.