World Of Gems Conference 2017 Proceedings Book

WORLD OF GEMS CONFERENCE V - 31 - SEPTEMBER 2017 these outlines has various possible facet arrangements. We have identified which common shapes and facet arrange- ments we intend to grade based on what we see coming through the lab and understanding the limitations of what we can do.We are working to address weight ratio.We are com- ing to terms with how to deal with taste or personal prefer- ence when there is no consensus. We are now able to measure in adequate detail and accuracy the variations we see in fancy shapes, such as clefts and lobes in hearts, and girdle variations.We are beginning to cor- relate this information with face-up appearance, and consider the grading impact of design and craftsmanship issues. Tra- ditional parameterization is not feasible for a fancy shape grading system, so other procedures must be developed for grading and estimation of grades. u FANCY CUT DIAMOND GRADES