The ‘Third C’
The term ‘cut’ is often confused with the shape* of the diamond (such as round, princess, pear-shape). However, in diamond grading the ‘cut’ refers to the craftsmanship of the diamantaire: the ability to unlock the beauty within a rough crystal by polishing individual, precise facets.
Ideally an artisan cuts a diamond to make the best use of light. When a diamond is cut to perfect proportions, light is refracted inside the stone, reflected from one facet to another, and then dispersed through the top of the stone. Extensive study of the laws of physics has allowed us to theorise and observe a range of proportions that achieve the maximum return of light.
If a diamond is cut too deeply, some light escapes through the opposite side. If too shallow, light escapes through the bottom of the stone before it can be reflected back to the viewer.
In order to maximise the ‘yield’ of any particular diamond crystal, a cutter may be tempted to depart from the range of ideal proportions.
For an explanation of the way light behaves within a diamond, click here to see an article from our June 2004 Newsletter.
People often comment that our diamonds “sparkle” more. This is due to our determination to choose the best cuts from parcels. The illustration here, of a tray of perfectly cut diamonds, contrasts with a tray of poorly cut stones. Which would you prefer to wear?