The 4Cs of buying diamonds refers to Cut, Colour, Clarity, and Carat. What are they?

You often hear and read about these “4Cs” but do you really know what they actually mean?

To the experienced jeweller, no diamond blemish is invisible, but to the untrained eye, every piece of diamond is the same. It might be complex to understand but before buying your diamonds, understanding the 4Cs will make you a smarter diamond buyer.

The Cut

Of all the 4Cs, this is considered to be the most important. Cut, as opposed to what most people think is not the shape of a diamond (e.g. princess, pear, round, marquise) but rather the facet arrangement of the stone. In simple words, it is the factor that has the greatest effect on the diamond’s beauty, how well it reflects light and create the diamond’s sparkle.

To cut a stone for excellent symmetry, proportions, and polish requires a high-level of dexterity and artistic mastery. The Gemological Association of America (GIA) defines the different Cut Grades as Excellent, Very Good, Good, Fair and Poor.

A GIA diamond cut scale chart
Photo courtesy of GIA®


The Colour

Next to cut, colour is one of the elements to consider when buying a diamond. The colour of a diamond is graded base on its yellowness (Z) to colourlessness (D) as determined by the Gemological Association of America (GIA). For diamonds, less is more. A diamond with almost no shade is considered to be of higher value than those with strong yellow or brown.

There are also diamonds in different colours such as black, blue, pink, cognac, and champagne which are called “fancy colour” diamonds which are graded by a different colour standard. Though colour is the 2nd most noticeable when looking at diamonds, there are some who prefer diamonds with colour.

A GIA diamond colour grading scale chart
Photo courtesy of GIA®

The Clarity

Diamond clarity is the assessment of internal characteristics called “inclusions” or outward characteristics called “blemishes”.  It measures imperfections such as pits, nicks, chips, crystals, feathers, and cavities or the lack thereof.

The GIA scale for clarity has 11 specific grade ranges under 6 categories namely: Flawless (FL); Internally Flawless (IF); Very Very Slightly Included (VVS1, VVS2); Very Slightly Included (VS1, VS2); Slightly Included (SI1, SI2); and Included (I1, I2, I3).

This 3rd C is the least of concern for buying diamonds as blemishes and inclusions are mostly not apparent to the naked eye.

A GIA clarity scale or grade chart

The Carat

Carat is one of the most heard of when talking about the 4Cs diamond but also the most misunderstood. People think it is the size, however, carat is the measurement of the diamond’s weight. The formula:

1 carat = 200 milligrams

Aside from this, a carat can still be split into 100 points, which allows accurate measurements until the hundredth decimal place.

Carat weight is one crucial factor for buying diamonds, especially for those with tight budgets. Remember that the bigger the carat weight, the higher the price will be.

A chart of 5 diamonds with different sizes positioned horizontal line entitled with carat weight each
Photo courtesy of GIA®

The Certification

In addition to the 4Cs, one more important factor to keep in mind when buying a diamond is the diamond certificate or diamond grading report. The diamond grading report contains easily understood information about the diamond which is prepared by an expert gemmologist.

White gold round halo engagement ring with petals shaped around the halo

Got any questions?

Monty Adams Jewellery Concierge has experienced jewellers ready to help you anytime. We take the time to explain the technicalities of your diamond. Book an appointment, today!



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