There are many considerations to take into account when buying a diamond.  I can help you maximize value and feel confident in choosing the right stone. White diamonds are assessed and priced by 4 characteristics, known as the 4 C's: color, clarity, cut and carat.  This seems cut and dry at first glance, but the subtleties are vitally important.  Some people value size and color, some are concerned with clarity and perfect cutting, and some want perfection in all categories.  Figuring out what is (and is not) important in your stone is more art than science, but like finding the right mate, it is a rewarding journey.

The Four (Five) C’s:


Color is rated from “D” – “Z”. A stone rated “D” is colorless.  This is highest rating.  Further down the alphabet, stones go to yellow/brown (which are valuable in their own way when the colors are distinct, as in a canary yellow or champagne diamond, which have gained popularity in recent years.)  In many commercial jewelry stores, it can be tough to find a stone that has a color rating is better than an “F” because the finest diamonds are not sold in large parcels, which is how many stores buy their diamonds.   My purveyors and I choose stones one by one and can get you stones with excellent color.


Clarity is rated on a scale just like color.  In order, clarity ratings are as follows: “F” (flawless – rarer than rare), “IF” (internally flawless), VVS (Very very slightly included), VS (Very slightly included), VS1,  “SI” (slightly included), “SI1”, “SI2”,”SI3”,  “I” (included).  Clarity is important, but not necessarily by its rating on paper.  Consider the type of inclusion – is it a crystalline flaw, something that looks like a little milky cloud or a black carbon fleck?  Is it right in the center of the stone or off on an edge obscured from view by facets?  If an inclusion is present but isn’t apparent to the naked eye, is it important?  Also keep in mind that all stones come from the earth and have distinctive markings (even if microscopic).  These can be seen like freckles/beauty marks or as an annoyance – it depends on what is important to you.  I am not bothered by inclusions invisible to the naked eye; in fact, I rather enjoy knowing that the stone is real and natural and identifiable.

Cutting is what determines a stone’s ability to refract light and is what will make it sparkly.  Exceptional cutting comes with an added expense, but in my opinion, it is important to get the best cut you can afford.  There are some cuts that maximize sparkle, like the round brilliant, and others that are quieter and more crystalline, like the emerald cut.  Beyond its basic shape, cutting is rated on its precision, symmetry, polish and proportions.   The way light refracts in a diamond is entirely dependent on the precision of the angles of the cut.  A shallowly cut stone will look larger, but won’t sparkle.   The same can be said for stones that are cut too deep.  The term for this is “bellied” – extra weight is left below the girdle of the stone; it detracts from the light refraction, but makes the stone weigh (and cost) more.  To me, the cut is the most important of the individual diamond attributes and can make or break the impact of the stone.  My purveyors seek out cuts that breathe life and fire into the stones we work with.


This is a unit of weight, not size.  Often people have a carat weight in mind when they start looking for a diamond.  It is good to have a rough idea to narrow the field, but feeling tied to a number can be detrimental.  I always recommend quality and “personality” over size.  Because this is one of the biggest factors in pricing a diamond, beware of deep “bellied” stones or shallow stones.   Because diamonds have very specific proportions that are ideal for light refraction (the sparkle factor), the stone may have a higher carat weight and be more expensive, but may not look as good as if it had been cut smaller to its ideal proportions.  My advice is not to get hung up on the carat weight of a stone.  Buy the most beautiful, not the biggest.


This is not one of the traditional “four C’s” but is important in understanding the subtleties of diamonds.  Diamonds are naturally occurring crystals that are then mined, cut and refined by human hands.  The specific way that each crystal forms is slightly different – where it’s from, what trace elements were around it while it formed, etc… Two stones may rate the same on paper, but they can look and feel very different.  Crystal qualities are widely varied and often explain why one stone sings and another does not.


When negative, fluorescence can have a cloudy oil slick like characteristic.  Fluorescence, in the past, was viewed as a negative quality; however, it is being re-evaluated in the field and can, in certain cases, can actually be an attribute.  It can add an internal glow and magic to a stone that is otherwise unidentifiable.  I know of many diamond dealers who seek out stones with this special type of fluorescence for themselves or their family members because it has that extra something that makes the stone feel alive.

Ratings, Certs:

Stones are rated by gemologists.  Ratings can be unofficial or they can be certified by a number of different accredited institutions.  Some stones come to me with formal certs and some do not.  For an official cert, the stone has to be sent out to an institution for assessment.  It usually takes a few weeks and costs about a hundred dollars plus shipping.  The main reason to get a cert is for insurance value.  The stone is assessed on its color, clarity, cut and carat.  Inclusions (even those invisible to the naked eye) are mapped out.  Recording your stone’s “birthmarks” and individual characteristics is helpful should you ever need to identify or replace your stone.


Diamonds are priced by balancing the aforementioned characteristics with demarcation lines based on the 4 C’s.  Price plays a part in every diamond purchase, so establish your comfort zone and look at stones in that general range.  Premium prices are paid for perfection in diamonds.  To maximize your value, think about what is important in your stone.  Price?  Size? Color? Shape? A diamond can be found to fit any price range by balancing the 4 C’s.

Something to keep in mind (VERY IMPORTANT):

All ratings are done by humans, and are therefore inherently imperfect.  Ratings depend on how fastidious the gemologist is.  Some are pickier than others; people can have bad days or be distracted… All ratings, to some degree, are subjective.  A friend of mine has sent the same stone to the same lab several months apart (as an experiment) and the stone came back with very different ratings.  Keep in mind that the 4 C’s determine the price of the stone, so many commercial stores give VERY GENEROUS ratings to lesser stones in order to sell the stones for more money than they may be worth. Ratings are an attempt to quantify the quality and value of a stone, but ratings are not worn on the finger. I have seen stones that rated beautifully on paper but felt dull and dead and I’ve seen stones that don’t look like much on paper that are absolutely spectacular.   This is why I have cultivated relationships with boutique purveyors who work exclusively with exceptional stones – some rate very high on paper and have a price to match, while some aren’t impressive in their ratings but are lively and gorgeous in person with great value in their price.

The Internet:

I cannot recommend buying diamonds online.  Big suppliers buy stones as uniformly rated parcels.  They are less expensive this way, but aren’t assessed individually and there can be a range of qualities within a single parcel.  The stones may have been given “generous” ratings to maximize profit.  If a diamond is already set, there may be a chip in the stone lurking under a prong or it may have other concealed flaws.  In this case, if it looks too good to be true, it probably is.  As I have discussed, the subtleties in diamonds are tricky and impossible to assess online, so working with a trusted source is key.

How to look at stones:

If possible, look at diamonds in every kind of light before making your choice.  The halogen lighting in jewelry stores is designed to make stones look as sparkly as possible, but no one lives under halogens all the time… try looking at the stone in natural light, incandescent light and fluorescent light if possible, sunlight being the best possible light.  Make sure not to get finger oils on the stone.  Use tweezers and be sure to wipe down the stone with a cloth before passing judgment.  If we are working long distance, I will photograph the stones in a variety of lights and conditions and let you know what my impressions are.

Finding the right stone:

When you have narrowed the field to only include stones you would consider buying, set the ratings aside and just look at the stones.  Choose a stone that has the right personality - don’t worry about which is the biggest or has the best color rating.   At first glance, white diamonds can all seem the same, but when you spend time with the stones, one will usually stand out.  Consider the overall impact of the stones and go with your gut.  It’s that simple.