Buying Diamonds

Buying Diamonds

Buying Diamonds

Buying Diamonds

Below you will learn the basic information you need to know if you are buying diamonds.  The information here is just the bare bone basics that any shopper should know before heading out to the boutiques.  Bija Bijoux is not your average diamond ring store, but we do offer custom design and have access to any diamond you may wish to purchase.  In store however, our diamonds are tiny, sparkly and stylishly set into funky jewellery designs by Canadian and U.S. jewellery designers.  We are of the less flashy set but would like to help you find exactly what you want as well as ensure that you know exactly what you should be getting, even if not from us.

Price comparison of diamonds is only possible if you are comparing apples to apples.  The 4C’s provide a way to objectively compare and evaluate diamonds: Carat, Colour, Clarity and Cut.


Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams.  The diagram below will give you a visual on carat size.

Just as a dollar is divided into 100 pennies, a carat is divided into 100 points. For example, a 50-point diamond weighs 0.50 carats. But two diamonds of equal weight can have very different values depending on the other three members of the Four C’s: clarity, colour and cut.  The majority of diamonds used in fine jewellery weigh one carat or less.
Because even a fraction of a carat can make a considerable difference in cost, precision is crucial. In the diamond industry, weight is often measured to the hundred thousandths of a carat, and rounded to a  hundredth of a carat.  Diamond weights greater than one carat are expressed in carats and decimals. (For instance, a 1.02 ct. stone would be described as “one point zero two carats”)
The carat, the standard unit of weight for diamonds and other gemstones, takes its name from the carob seed. Because these small seeds had a fairly uniform weight, early gem traders used them as counterweights in their balance scales. The modern metric carat, equal to 0.2 grams, was adopted by the United States in 1913 and other countries soon after. Today, a carat weighs exactly the same in every corner of the world.

Diamond colour is all about lack of colour, ironically.  Diamonds are valued by how closely they approach colourlessness – the less colour, the more they are worth.  (The exception to this is fancy-color diamonds, such as canary yellow, pink, brown or  blue)

Most diamonds found in jewelry stores run from colourless to near-colourless, with slight hints of yellow or brown.  The Gemological Institute of America, known to professionals in the jewellery industry as GIA, has a standardized colour grading system.  GIA’s color-grading scale for diamonds is the industry standard.  The scale begins with the letter D, representing colourless, and continues with increasing presence of colour to the letter Z, or light yellowish brown.  Each letter grade has a clearly defined range of colour appearance.  Diamonds are colour-graded by comparing them to stones of known color under controlled lighting and precise viewing conditions.  Many of these colour distinctions are so subtle as to be invisible to the untrained eye but these slight differences make a very big difference in diamond quality and price.
Before GIA developed the D-Z Color Grading Scale, a variety of other systems were loosely applied.  These included letters of the alphabet (A, B and C, with multiple A’s for the best stones), Arabic (0, 1, 2, 3) and Roman (I, II, III) numerals, and descriptions such as “gem blue” or “blue white”.  The result of all these varied grading systems was inconsistency and inaccuracy.  Because the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems, they chose to start with the letter D—a letter grade normally not associated with top quality :).



Because diamonds are naturally formed deep within the earth, under extreme heat and pressure, they often contain unique identifying marks, either internal (inclusions) or external (blemishes).

Diamond clarity refers to the absence of these inclusions and blemishes.  Diamonds without any “birthmarks” are rare, and rarity affects a diamond’s value. Using the GIA International Diamond Grading System™, diamonds are assigned a clarity grade that ranges from flawless (FL) to diamonds with obvious  inclusions (I3).
Each diamond is unique.  None is absolutely perfect under 10× magnification, though some come quite close. Known as Flawless diamonds, these are exceptionally rare.
The GIA Clarity Scale contains 11 grades, with most diamonds falling into the VS (Very Slightly included) or SI (Slightly Included) categories. In determining a clarity grade, the GIA system considers the size, nature, position, colour or relief, and quantity of clarity characteristics visible under 10× magnification.
Flawless (FL) = No inclusions or blemishes are visible to a skilled grader/gemologist using 10× magnification.  Internally Flawless (IF) = No inclusions and only blemishes are visible to a skilled gemologist using 10× magnification.  Very, Very Slightly Included (VVS1 and VVS2) = Inclusions are difficult for a skilled gemologist to see under 10× magnification.  Very Slightly Included (VS1 and VS2) = Inclusions are minor and range from difficult to somewhat easy for a skilled grader to see under 10x magnification.  Slightly Included (SI1 and SI2) = Inclusions are noticeable to a skilled grader under 10x magnification.  Included (I1, I2, and I3) = Inclusions are obvious under 10× magnification and may affect transparency and brilliance
Like the color scale, GIA’s clarity grading system developed because jewelers were using terms that were easily misinterpreted.  Today, even if you buy a diamond in another part of the world, the jeweler will likely use terms such as VVS1 or SI2, even if his or her language is French or Japanese instead of English.
Cut is the factor that fuels a diamond’s fire, sparkle and brilliance.  The cut can make or break the beauty of a diamond.

The traditional 58 facets in a round brilliant diamond, each precisely cut and defined, are as small as two millimeters in diameter.  Without this precision in the faceting, or cutting, a diamond would not be as sparkly and beautiful as it is.


Though extremely difficult to analyze or quantify, the cut of any diamond has three attributes: brilliance (the total light reflected from a diamond), fire (the dispersion of light into the colors of the spectrum), and scintillation (the flashes of light, or sparkle, when a diamond is moved).
An understanding of diamond cut begins with the shape of a diamond. The standard round brilliant is the shape used in most diamond jewelry. All others are known as fancy shapes. Traditional fancy shapes include the marquise (points at each end), pear, oval and emerald cuts. Gaining in popularity over the years are the other fancy shapes, such as hearts, cushions, triangles and princess cuts.
As a value factor, however, cut refers to a diamond’s proportions, symmetry and polish. For example, look at a side view of the standard round brilliant. The major components, from top to bottom, are the crown, girdle and the pavilion. A round brilliant cut diamond has 57 or 58 facets, the 58th being a tiny flat facet at the bottom of the pavilion that’s known as the culet. The large, flat facet on the top is the table. The proportions of a diamond refer to the relationships between table size, crown angle and pavilion depth. A wide range of proportion combinations are possible, and these ultimately affect the stone’s interaction with light.
In early 2005, GIA unveiled a diamond cut grading system for standard round brilliants in the D-to-Z color range. This system, the product of more than 15 years of intensive research and testing, assigns an overall diamond cut grade ranging from Excellent to Poor.