Diamond cut: what is the cut of a diamond? is the cut of a diamond important? how important is the cut of a diamond?

There are two ways to look at the 'cut' of a diamond.  The first way many people are actually referring the shape of the diamond.  Is it round, is it square, is it heart shaped, pear shaped so forth and so on.  The second refers to a how well-proportioned the dimensions of a diamond are, and how these surfaces, or facets, are positioned to create sparkle and brilliance.  Both are important however the second is less important that you would think (when shopping with us particularly and we will explain why!).

FIRST: CUT; as when its referring actually to shape:
Many people refer to cut as the shape of the stone.  Is it a round or a pear shape, a marquise or an oval, a princess cut or a radiant an so many more options.  You can learn more about them on our diamond education pages.  That being said there are aspects of "cut" or shape that are important.  In the diamond business in general we call this the "make" of the stone.  Is an oval shape a long oval or a short one, how about a elongated radiant cut or a square one.  The make, and shape of stone can make a dramatic difference in the price of diamond.

SECOND: CUT; as when its referring to proportions.
This refers to how a diamond is actually angled and proportioned meaning how it lets in, and pushes out light.  This could dictate how much sparkle or the type of sparkle a diamond has.  First I think its important to go over some basics. One thing to note is that GIA only grades cut grade of round brilliant cut diamonds.  This is very important to note and shows the importance of make.  Additionally GIA's cut grade does not factor into it other rounds like European cut diamonds or Old Mine Cut's.  Here are the cut grades we use at Velvet Box Society as we follow the standards set forth by GIA with some additional notes.

Cut grades range from:
Excellent
Very Good
Good
Fair
Poor

GIA's cut grade is derived from a combination of Brilliance, Fire, And Scintillation as derived by the angles and proportions of the diamond.
They are defined as:
Brilliance: reflection of white light
Fire: is the dispersion of light into the colors of the rainbow
Scintillation is the play of contrast between dark and light areas or a diamonds sparkle

Cut grade is a combination of the make, polish, and symmetry.  Those factors take into account:
Table: The largest facet of a gemstone generally located at the top (except in rose cuts)
Crown: The top portion of a diamond extending from the girdle to the table
Girdle: The intersection of the crown and pavilion which defines the circumference of a diamond, the widest point generally also defined as where you would measure diameter or one girdle edge of a diamond straight across to the opposing side
Pavilion: The bottom portion of a diamond, extending from the girdle to the culet
Culet: The facet at the bottom of a gemstone.
Depth: The height of a gemstone measured from the culet to the table

What Is The Most Expensive Cut Of A Diamond?
​This is a tricky questions.  If by cut you are referring to shape then round brilliant cut would take the cake (all other factors being equal). That being said when you ask about the cut of a diamond the answer is a bit more tricky.  Most retailers, particularly online retailers, will push cut as the most important, or one of the most important factors in a diamonds quality however the truth is, its not.  Shocking yes.  We can confidently say that because in the wholesale market the cut grade actually effects the price the least!  So something  that effects the price the least would be considered less important than other factors the effect price more.  That being said there are catches to this.  For example you can have a really spready AMAZING looking stone with a good or even fair cut grade.  Sometimes these are "spreadier" stones meaning  the weight 1 carat and look like 1.25 carat stones.  The light performance is so close you physically could not tell the difference, except on paper.  But at the end of the day you're not walking around with paper on your hand, you are with a rock.  Retailers like to tout cut as the most important factor as this is where they are making their biggest mark up usually.  Now one exception to this rule would be a 1 carat stone that looks like a half carat stone.  This stone could have lots of light loss.  So we can't say in the broad range its not important because it is.  In fact many retailers sell this type of deep stone and that's the reason GIA invented  the cut grade.  It helps shed light on a particular aspect of a diamond.

For more information about diamond cut check out our diamond education pages! 
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We don't leak all of our knowledge in our blog so if you are shopping for an engagement ring, a custom engagement ring, or an antique engagement ring never hesitate to contact us as we are happy to guide you through the process!

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