Scientists from the Scientific & Research Institute of Experimental Physics lab at the Russian Federal Nuclear Center, along with directors from Kristall Production Corp., diamond manufacturer in Smolensk, Russia, say they’ve developed a machine that can measure a diamond’s charm.

According to the Smolensk Gemological Center, the Charm Index is defined “on the basis of measured optical properties of a diamond’s brilliance that can be perceived by an observer’s eye.” After measuring a polished diamond’s optical properties, technicians use a set of defined mathematical formulas to determine a number between zero and 10—the brilliance beauty index. That number represents a diamond’s “charm.”

Optical properties that are reportedly measured are brightness (or brilliance intensity), dispersion (or fire), sparkle (or scintillation), and “the geometry of the brilliance pattern.” Then, using an algorithm, the Charm Index is determined, according to SGC, by “quantitative assessments of the diamond’s brilliance, obtained by the trained independent observers, in the process of the multiple viewing of films in the atlas of brilliance.”

“The extent to which an optical property of brilliance influenced the generalized assessment, that is Charm Index, was empirically determined based on the most precise data array obtained by the observers.”