The 4 “C”: Carat, Color, Clarity, Cut

The maximum quality in all respects.

Since diamonds have a very high value, it is essential to have a measurement system for the comparison of the multiple, different qualities. To this end, between the years 1940 and 1950, the G.I.A. (Gemological Institute of America) developed the International Diamond Grading System™ and 4 C.


The carat is the standard unit of measurement of the weight of diamonds and other precious stones, and takes its name from the carob seed which in the past was used as an element of comparison.

It was only in 1913 that the United States first, and the other nations to follow, adopted the modern system of “metric carat”, which corresponds to 0.20 grams and is divided into 100 points.

diamonds carat chart

Those responsible for certification of diamonds possess instruments for measuring weight extremely accurate, up to 6 decimal numbers.


The stones of highest value are those totally colorless, commonly known as 'white'. The more colorless the diamond is, the more it increases in value. Colorless diamonds correspond to only a small percentage of those extracts, as more than 90% of the diamonds have nuances of base yellowish or brown.

There is a minimum quantity of diamonds from natural colors more or less intense: yellow, orange, pink, green, blue or red, who by virtue of their rarity can reach very high prices.

Before the G. I. A. created the scale of gradation D-Z, there were different assessment systems. Among the other letters of the alphabet (A, B, C) with the multiple for the better stones, the system of Arabic numerals (0, 1, 2, 3) or Romans (I, II, III), and also written descriptions as “River”, “Top Wesselton”, “blue gemstones” etc.

diamonds color chart

Given that the inventors of the scale of color gradation G.I.A. wanted to create something completely new, they decided to begin their classification with the letter “D”, because it had never been used before to define the diamonds of the highest quality.

Diamond Love Bond doesn't sell diamonds categorized as color I or less.


There are also other conditions, which may significantly affect the cost of a diamond: one of these is the Fluorescence.
When exposed to invisible ultraviolet rays, diamonds can give rise to phenomena of fluorescence, appearing to glow blue and less often green, yellow, orange or a combination of these colors. This glow, called fluorescence, lasts only as long as the diamond is exposed to ultraviolet rays. It is important to note the fluorescence in a diamond, because the high intensity of the phenomenon affects the color of the gem.

Diamond Love Bond sells only diamonds with fluorescence “None” (absent).


Since diamonds were formed in the depths of the earth, in extreme conditions of heat and pressure, each of them has specific and unique “birthmarks”, identification marks both internal (inclusions) and external (blemishes).

diamonds clarity chart diamonds GIA clarity scale

The purity of the diamond is a consequence of the absence of inclusions and imperfections.
Diamonds with a total absence of “birthmarks” are rare, and this characteristic gives value to the diamond.

The G. I.A. International Diamond Grading System has defined a scale of purity to eleven levels ranging from FL (flawless) to I3 (Included 3).

As for the color, the G. I.A. Grading System was developed because the jewellers used terms such as “loupe”, “pique” or “clean”, of dubious interpretation.
Today, in any part of the world in which you are buying a diamond the most used words in all languages are those established by G.I.A.

For the project Diamanti in Banca (Diamonds in the Bank) reserved for the clientele of UBI BANCA Diamond Love Bond has selected exclusively diamonds IF.

For a direct customer, with clearly-defined requirements, Diamond Love Bond while privileging always Clarity IF, may also select Clarity VVS in categories up to 3 ct. and Clarity VS in the higher classes to 3 carats.


Diamond Love Bond sells exclusively diamonds in which all three measures of quality are “Excellent“. For the diamonds with one, two or three features of the “Very Good”, Diamond Love Bond attaches a discount between 5% and 11% of its price list.

diamonds GIA cut scale

Diamond Love Bond does not sell diamonds with even a single characteristic “Good“.

To get an optimal response to light (refraction, reflection, brilliance, sparkle and fire) a diamond must be cut in a perfect way, respecting rigid mathematical calculations to generate the geometric designs, dimensions and angles required for the different facets.

Achieving perfection is determined by the skill of the master cutter.
The traditional cut and more widespread is the “round brilliant” consisting of 57 or 58 facets. There are other types of forms: drop, heart (59 facets), navette or marquise (58 facets), emerald (48 or 50 facets), oval (56 facets), princess (76 facets), radiant (62 or 70 facets) etc.

diamonds cut chart

Without the precision and perfection of cut, a diamond loses much of its beauty. The “allure” of each diamond depends, more than anything else, on the quality of the cut.

diamonds cut chart

Although extremely difficult to analyze and quantify, the cutting of every diamond has three attributes:

  • brilliance - the total light reflected from a diamond
  • fire - the dispersion of light into the colors of the spectrum
  • scintillation - the flashes of light or sparkle when a diamond is moved.

As a value factor, though, cut refers to a diamond’s proportions, symmetry and polish.

In early 2005, after 15 years of intense research and testing, the G.I.A. unveiled a Diamond Cut Grading System for standard diamonds round brilliants in the D-to-Z color range. This system assigns an overall cut diamond grade ranging from Excellent to Poor.