December's birthstones offer three ways to fight the winter blues: tanzanite, zircon, and turquoise—all of them are best known for beautiful shades of blue.
The Science of Scintillation™
|Scintillation Metrics and Maps
Scintillation is sparkle. Scintillation is the play of white and colored flashes of light seen when the diamond is viewed in motion. Viewable with the naked eye, scintillation is the life of the diamond.
The two dynamic aspects of sparkle are called flash scintillation and fire scintillation.
In 2007, the research team at AGS Laboratories published a landmark paper detailing their findings on diamond cut. This paper was the first of its kind to be published in a major optical sciences journal and was also one of the first major articles to discuss The Science of Scintillation™:
This research serves as both the foundation and inspiration behind the scintillation metrics and maps.
Light and Movement
Without light, diamonds can’t sparkle. As light is a key ingredient, diamonds with the highest potential for sparkle find light in the broadest ranges of commonly encountered illumination environments and redirect the light to the observer’s eye.
The other key attribute is movement, which sets the scintillation performance apart from its light performance. A motionless diamond in broad diffuse lighting cannot demonstrate the beautiful display of scintillation. It is movement that causes the flickering of sparkle across a diamond, whether it is the diamond, the observer, or the light source that moves.
Metrics and Maps
The main principle behind the AGS Laboratories’ scintillation analysis is that only diamonds exhibiting the highest scintillation potential should receive the best “sparkle” score. A key characteristic of a diamond with very high scintillation potential is the sparkle seen across the full crown of the stone. A poorly cut stone could have “dead” or underperforming areas in the table, bezels or stars, where no flash or fire is seen.
According to the AGS Laboratories’ scintillation metrics, diamonds that score a 0-0 have attained the highest possible grade for both flash scintillation and fire scintillation. These stones exhibit the white and colored sparkles across their full crown, “finding light” over a broad range of movement, with minimal underperforming areas.
The value of scintillation maps is they compress the dynamic display of a diamond in motion into a single static image for use in a report. A 3-D model of the diamond is ray traced over a series of orientations to create an array of data and a series of color-coded maps. These snapshots of data are then averaged and overlaid to create a cumulative color-coded map demonstrating important factors such as facet size, flash potential and dispersion.