Plot : Map of Inclusions It is impossible to achieve absolute consistency in diamond grading because nature does not give absolute demarcations when it creates diamonds. Therefore, grades may vary somewhat from lab to lab when a diamond is somewhere between two grades. But the main thing most consumers want to know about a diamond is very simple: "Does the diamond have any flaws I can see with my naked eye?" Usually you will be answer this question only from the map, or plot, of the diamond. If a diamond has a clarity grade of VS1 or better, you will not see anything with the naked eye. However, it becomes a little harder to make that statement about a VS2, because placement of the inclusion will make a difference. If the main inclusion in a VS2 or SI1 is directly under the table facet (the large facet at the top center), you might be able to see it with the naked eye. If the clarity grade is VS2 or less, we recommend examining the plot to see the placement of the major inclusions. See our Glossary of Terms to find out more about any of the terms used on your certificate, such as feather, pinpoint, cloud, or natural. For a more comprehensive, searchable glossary including details about famous diamonds, trade terms, and notable people in the history of diamonds, visit the GIA Diamond Dictionary at the GIA Web site. For brief explanations of the terms used on GIA Diamond Grading Reports, visit the page that explains the new report formats and services. Visit the site for a given laboratory to understand how they define the grades they use on reports, or if you have any other questions about a diamond certificate. Go here for links to the most respected laboratory sites -- these will take you directly to the certificate pages on each site. Back to: How to Read a Certificate