Beyond the 4 C:s

HIGH-QUALITY DIAMONDS

To get a more accurate value of diamonds, there are other factors to consider besides the 4 C’s. These factors provide more detailed information about the visual appearance of the diamond and significantly affect its price. Remember that if two diamonds with the same parameters differ in price, it is always for a reason. Read below about what can make diamonds differ in quality and price.

Ideal Grinding

The Round Brilliant Cut is the only diamond shape that comes with a Cut Grade on the diamond certificate. The cut determines the amount of light that the diamond can refract to produce the desired brilliance.
Although Excellent is the highest and most sought-after grading, it is relatively easy to obtain from a diamond cutting perspective. The ‘Excellent’ Cut has a relatively large span, which makes it easy to achieve. This is why it is imperative to buy a diamond that is not only rated as Excellent but is also within the ideal range.

Although round diamonds are the only shape that comes with a Cut Grade on the certificate, the other shapes have ideal proportions that are good to consider when buying such a diamond. Feel free to read more about fancy shaped diamonds here.

Even though Round diamonds is the only shape that comes with a Cut Grade on the certificate, fancy shapes does have ideal cuts to keep in mind when purchasing. Please read more about fancy shaped diamonds here

Symmetry

Symmetry describes the variations of the parameters in the diamond’s proportions. Such proportions may be a lack of roundness, variation in crown height/pavilion depth, that the table is staggered or not parallel to the culet, or an uneven girdle.

Grading system:

Excellent – Very Good – Good – Fair – Poor

Polishing

The polish describes and evaluates the presence of external characteristics of a polished diamond. These properties are caused during the cutting process, or later on by improper handling of the diamonds. These characteristics can include scratches, polishing lines, beards, burn marks and rubbed bevel edges.

Grading system:

Excellent – Very Good – Good – Fair – Poor

Fluorescence

Fluorescence is the emission of visible light when an object (diamond) is exposed to ultraviolet light. 35% of all diamonds exhibit some degree of fluorescence.

There is no visible difference between a diamond that does not have none – medium fluorescence in normal daylight.

Fluorescence is harmless to the diamond but can affect the diamond’s luster if it is graded strong or very strong. However, lackluster and milky diamonds are usually caused by other factors. (Read more under Luster)

A.P. Shaps offers customers the opportunity to see loose diamonds under UV lamps and normal light if they wish to purchase a diamond with fluorescence.

Luster

Luster is not rated on the diamond certificate and can only be determined by a trained gemmologist or diamond grader. Although Lyster is not graded on the certificate, it has a significant effect on the price. This is a common reason why a “perfect” diamond (high color and clarity) can be sold at a low price.

Luster is mainly caused by small, spotty inclusions or crystals (clouds) that cover a large area inside the diamond. Strong or Very Strong fluorescence can in rare cases cause a poorer luster, giving the diamond a milky or hazy appearance. A diamond with Excellent luster shows good brilliance.

BGM (Brown, Green, Milky)

BGM – brown, green and/or milky – is a well-known term in the diamond industry. Diamonds tend to come in brown and green shades and shades. So, for example, when you buy a lower graded (in color) diamond, it doesn’t necessarily have to be yellowish. It can have a brown or green undertone, making the diamond look dirty instead of warm as is the case with yellowish diamonds.

Milky is a trade name for diamonds with a low luster and a hazy appearance.

Therefore, you should always buy a diamond without BGM.

Bowtie Effect

A diamond bow tie is a darkened area that runs across the diamond’s width. All elongated diamond shapes, such as the oval, radiant, pear and marquise, have some degree of a bow tie. The diamond bow tie is an imperfection formed when a diamond is cut and hence is a less desirable feature. Thus, when shopping for a diamond,  you may want to avoid large bow tie effects.

How much the bow tie affects your diamond depends on how well the diamond is cut. A well-cut diamond will show a minimal bow tie effect; however, there will always be some evidence of a bow tie effect.  In the end, you must decide how much of a bow-tie effect you’re willing to accept.

Ethical diamonds

Read about the Kimberley Process