Diamond Cut And Proportions

cut proportionsThere are 3 factors that determine diamond cut-

Brightness (Brilliance) – the combination of all white light reflecting from the surface and interior of a diamond.

Fire – the colored flashes that can be seen in a diamond. Mostly from the angled crown facets.

Scintillation¬†– the flashes of light seen in a diamond when you move it from side to side….the “sparkle”.

A diamond’s “make” is a trade term referring to how well or poorly a diamond is proportioned, referring to the diamond cut. If I say that a diamond is “well made” it means that it was well cut and has very good optical performance. You might hear…. “poor make”, “off make”, etc.

Once, I told a customer that a diamond was “well made” and they thought that the diamond was a diamond grown in the laboratory….. she thought we actually made the diamond.

Diamond cutters are generally highly skilled and they don’t cut a diamond with a “poor make” by accident. Anytime there is a departure from a proper diamond cut it is done for one reason…. economics.

The price of a piece of diamond rough that is available on the market is pretty well standardized. To cut a well-proportioned diamond or to cut a poorly proportioned diamond can take a similar amount of time… it will not take 2, 3, or 4 times the amount of time to cut a well proportioned diamond.

Many customers often need help in visualizing the carat size of a diamond to its physical size. If you also have the same issue, click here for a free downloadable carat size chart for visualization purposes.

Diamond cutting and diamond cut – a quick primer

– In cutting a finished diamond from a piece of diamond rough, the diamond cutter will loose around +/- 50% of the weight of the diamond rough. The diamond cutter will try to make sure that they cut away any inclusions that are in the diamond rough as they cut. Sometimes they will make adjustments to the finished diamond in order to cut away just a bit more of an inclusion…. the cutter will end up having a higher diamond clarity but a lower diamond cut.

– Diamond cutting houses will tend to specialize in certain types of finished diamonds. Some will cut fancy shapes, some will cut “Ideal Cut” diamonds, and some will specialize in squeezing as much finished weight out of a piece of diamond rough as possible. There is a market for all of these types of finished diamonds…. some people want big diamonds but they don’t care about diamond cut, they just want to tell people how much their diamonds weighs!

– If a diamond cutter is planning out a diamond and it looks like he could have an “excellent diamond cut” diamond that would have a finished weight of 0.97ct. or if he makes a few adjustments (making the girdle a bit thicker) he could have a “very good diamond cut” diamond that weighs in at 1.02ct., he probably will opt for the heavier stone because it will bring in more $.

– Oddly shaped rough stones are further segregated and used to fashion less desirable fancy shapes depending on their size and shape. Usually, they are cut to shallow or overly deep proportions. As a result of being cut to retain weight instead of the sparkle factor, these diamonds have lesser brilliance and luster.