A diamond master set, or sometimes called a diamond color master set, is a collection of diamonds use to grade the color of other diamonds.
Both the GIA and the AGS offer color master sets, or I should say they will grade diamonds for inclusion into a set. The GIA does not actually sell sets, not sure about the AGS but I don’t think so.
In order for a diamond to be included into a set by the GIA there are quite a few criteria the diamond must follow to be considered:
- Diamonds must be at least 0.25ct in size.
- Clarity grade not lower than SI2 (there can be no visible inclusion when viewed from the pavilion so higher clarity has a better chance of acceptance).
- Thin to thick girdles only.
- Diamonds in the color range from D through J can contain no fluorescence. Even a diamond that has been previously graded as having no fluorescence may have trace fluorescence that would exclude the diamond.
- Girdles that are heavily bearded, wavy, have large naturals or extra large facets will exclude a diamond.
- Crown or pavilion angles must not be noticeably shallow or deep.
Some people go out and buy a completed set, others build their own. I have been working on finding diamonds that can be classified as color masters for many years. I have found a few but still working to build my collection…
Back in 2007 the GIA sent me the procedures for submitting diamond for GIA master color comparison set grading, which I am making available here for reference.