AGS 0, AGS 000 and AGS Triple Zero - Ideal Cut Diamonds

American Gem Society Laboratories (AGSL) uses a 0-10 grading scale with 0 being the best (Ideal). One can think of the top grade as having “zero deductions”. This scale applies to color and clarity grading as well as AGS cut grading. Traditionally, diamonds referred to as AGS Triple Zero were diamonds receiving grades of zero in color (D), zero in clarity (Flawless), and zero in cut (Ideal) on an AGS Diamond Quality Document.

While AGS 000 was originally a term for a D Flawless diamond with Ideal cut, over time a different usage of the terminology began to emerge. Because of a growing interest in cut quality, sellers began using the term ‘Triple Zero’ in reference to the three cut aspects that had to be ideal in order for the overall cut grade to be ideal: Proportions, Polish, and Symmetry (pre-2005) and Light Performance, Polish and Symmetry (LP based reports - post July 2005). AGS 000 diamonds are now understood by the market to be any AGS diamond with an Ideal cut grade, without regard to the diamond’s color or clarity grade.

The increase in this alternate usage at first caused the AGS to redefine Triple Zero on their website FAQ, and eventually to remove the question from the FAQ altogether. According to the AGS, the usage was ultimately allowed to evolve into common parlance: "Technically an AGS triple zero was a diamond with a 0 grade in cut (Ideal), 0 in clarity (IF or Flawless) and 0 in Color (D). AGS 000. However, sellers (internet sellers at first) started calling diamonds with 0 cut triple zeros because proportions, polish & symmetry all had to be 0 to get the cut grade AGS 0. AGS tried to address this, but it has entered the modern lexicon. It became an ‘if you can’t beat them, join them’ thing."

The AGS cut grading system predated by many years the system now in place by the GIA (Gemological Institute of America). The GIA uses a different methodology and a different grading scale that does not include the term “ideal”. The highest cut grade possible in the GIA system is Excellent. The three cut related grades on a GIA report are Polish, Symmetry and Overall Cut Grade. Thus, Triple Excellent equates to the highest grade for cut quality. It is also referred to as GIA TripleEx, GIA Triple EX or GIA EX EX EX.

The GIA provides an overall cut grade only on round brilliant diamonds. The AGS Lab performs cut grading on a variety of diamond shapes including rounds, princess cuts, ovals, emerald cuts and certain cushion cut diamonds. For more information on the differences between the two labs, please see our article on AGS vs GIA.