The new Cut Cards
Sometimes we seem stuck in terminology that is more confusing than helpful. When talking about the beauty and light performance of a diamond there have been some noteworthy attempts to make things simpler. The new little plastic cards that have a three bar scale describing light performance are an excellent example. They have three bars with a scale that ranges from Low to High or Good to Ideal the bars are usually in the same order, Brightness or White Light for the top bar, Colored Light, Dispersion or Fire for the second and Scintillation or Sparkle for the third.
I can see there is still room for confusion. What the systems were originally designed for was to help quantify the things we look for in a diamond.
The brilliance or total light return in a diamond. How much of the light that enters the diamond from typical viewing angles comes out from those same angles. Since some of that light has been diffracted it’s not just white light. This comes predominately from the proportions of the diamond which has it’s own grade.
We also wanted to determine how much of the light was broken into it’s prismatic colors or what we call “Fire“. It used to be that we had the notion that Americans liked Fire or colored light and Europeans liked Ice or white light and we allowed grading to encompass both styles. Today I’m not sure if that was not just a way to give cutters more latitude. The aspect of cutting that creates the greatest amount of fire is the symmetry of the diamond which will have it’s own grade.
The last thing we wanted to measure was the polish of the diamond. It turns out that polishing lines can affect reflectivity and even deflect some of the light that would have entered the stone. Polish has always been graded separately but by using new techniques we have brought it to new levels of measurement. What we call Scintillation are the flashes off of the stone. Most of these come from the surface and a better polish will give better scintillation. Unfortunately the term seems to have multiple definitions within the industry which can be misleading.
