The 4Cs principle is an international standard for evaluating diamonds based on four criteria: carat (weight), cut, color, and clarity. It is these four characteristics, and not just the size of the stone, that determine a diamond's price and appearance. At BELLER, we work exclusively with GIA-certified diamonds, which provide all four parameters in a single document.
Carat: weight, not just size
Carat (ct) is a unit of a diamond's weight, not its size in millimeters: 1 ct is 0.2 grams. The price increases non-linearly with carat, because larger rough stones of suitable quality are rarer, and nature does not distribute them equally: the larger the raw material, the longer it took to form before it ever reached the jeweler's hands. In our Promise collection, a ring with a 0.30 ct round brilliant diamond starts from 10,950 PLN, a 0.50 ct from 24,500 PLN, and a 1.00 ct from 70,500 PLN, which is almost seven times more expensive than a stone three times smaller. It's good to remember this before asking "how many carats," because it's not the number that determines whether the ring takes your breath away when it finally lands on your finger.
Cut: the parameter that determines brilliance
The cut describes the proportions and angles at which the jeweler has cut the stone, and it is responsible for how the diamond reflects light. This is where craftsmanship meets physics: each facet must be set at an angle of a fraction of a degree so that light entering from above returns directly to the viewer's eye, instead of escaping sideways and fading into the stone's darkness. The GIA certificate evaluates the cut on a scale from Excellent to Poor, taking into account, among other things, the crown angle and the pavilion angle of the stone. A diamond with a smaller carat but an excellent cut often sparkles more brightly than a larger stone with an average cut, which is why at BELLER we treat this parameter as priority number one: it is this brilliance, not the stone's weight itself, that makes someone gasp when the ring catches the light for the first time.
Color: from colorless to slightly creamy
Color is graded on the GIA scale from D to Z, where D signifies a completely colorless stone, and subsequent letters indicate an increasingly visible, warm hue. The closer to colorless, the more purely the diamond transmits and disperses light, as if looking through a drop of the purest water. The most frequently chosen range by our clients is D-E, meaning colorless or nearly colorless stones where the hue is not noticeable to the naked eye even upon careful examination. This is one of those parameters that is worth taking care of not because someone will notice it at first glance, but because the knowledge of the stone's complete transparency provides calm assurance with every subsequent glance at one's own hand.
Clarity: inclusions that are (usually) invisible
Clarity describes the number and visibility of natural inclusions within the stone, graded on a scale from FL (flawless) to I (inclusions visible to the naked eye). These tiny inclusions are essentially nature's fingerprint: proof that the stone formed millions of years ago under immense pressure deep within the earth's crust, long before anyone thought of a ring. Stones in the VVS1 and VVS2 grades have inclusions visible only under ten-times magnification, so to the unaided eye, they look identical to a flawless diamond, and yet they carry the same authentic history as any other natural diamond.
How the 4Cs affect the final price
None of the four parameters works in isolation from the others: a large stone with a poor cut can look worse than a smaller but perfectly cut one, and very high clarity with an average cut will not give the same visual effect. Therefore, choosing an engagement ring is a bit like putting together a personal story from four different chapters at once, where each choice affects the others, and the final effect depends on what is truly important for a particular couple: size, brilliance, subtlety, or the certainty that the stone is exceptionally clean. At BELLER, each client receives a GIA certificate with a full breakdown of the 4Cs, and in our ateliers in Warsaw and Krakow, we show live how these parameters look in various combinations and price ranges, so that the decision can be made calmly, not under time pressure or from a salesperson.
Frequently asked questions about diamond 4Cs
Which of the 4C parameters is most important?
Cut is most often indicated, as it determines the stone's brilliance regardless of its size. A well-cut, smaller diamond can look more impressive than a larger stone with an average cut, and it is this initial sparkle in the light that often remains in memory for a lifetime, not the carat number written on the certificate.
Is the difference between D and G color visible to the naked eye?
In most cases, no, especially in a setting and under artificial light. The difference is easier to spot only when directly comparing stones side-by-side in natural light.
What exactly does a GIA certificate mean?
It is an independent evaluation of a diamond issued by the Gemological Institute of America, describing all four 4C parameters. Every BELLER diamond above 0.3 ct receives such a certificate.
Does a larger carat always mean a better diamond?
No. Carat only refers to the stone's weight, while its appearance and quality are determined jointly by cut, color, and clarity. A smaller stone with higher parameters often looks better than a larger but lower-quality one.
Where can I see different 4C combinations live?
At the BELLER atelier at ul. Mokotowska 71 in Warsaw and at ul. Szczepańska 9 in Krakow, where a consultant will show live how the same parameters look in different combinations.
Choosing a diamond for an engagement ring is one of those decisions that should be made without haste, with a full understanding of what you are paying for and why. See the full collection of engagement rings or read more about BELLER certified diamonds. Related entries: how to read a GIA certificate and how to choose an engagement ring.