Since 1914



Not all diamonds are the same and their beauty cannot be determined from the certificate alone. The reason for this is that ‘a good diamond cutter does not cut good diamonds’. Sounds strange at first until you understand why…

Promise image 1 350 x 200

The most significant attribute that determines a diamond’s value is its weight in carats. This means that the best diamond cutters will try to save as much weight from the original rough as possible when polishing the diamond, regardless of whether that makes the diamond sparkle just a little less.


This sparkle, sometimes called scintillation, is created when a diamond’s cut forms a prism. This prism allows light to enter a diamond through the top and break up into red, blue, yellow, orange and white light, whilst bouncing around the internal mirrors created when its facets were polished.



Every facet plays its role in creating this prism, from its angle and shape to its symmetry. Every tiny amount of weight saved by stretching a facet or changing an angle will reduce the sparkle, as either the light doesn’t break up or leaks out the bottom of the stone.

Facet picure for web site


With over 100 years’ experience, Chalfen of London believes the quality of a diamond should not be measured by its colour and clarity alone but rather the amount of sparkle that the diamond exhibits. This is impossible to read from the information written on a diamond’s certificate, even under the title cut grade.


Chalfen of London promises that every diamond has been selected for sparkle by eye, whether certificated or from one of our two house diamond ranges. After all, it is this sparkle that separates a diamond from any other material on the planet.

diamond ring 328x238