The name diamond comes from the Greek language "adamas", which translates as: "invincible", "indestructible". The name diamond was well known in antiquity. In India, it was called "irra", and in Sanskrit it was called "vajira", a word that defined everything that was hard. The Arabs called it "al-mas" - meaning "the hardest", from which comes the Slavic name "almaz" (diamond).

The diamond is the most famous of the four stones considered "precious": the diamond, the ruby, the sapphire and the emerald.

From a chemical point of view, diamond is the only precious stone that is composed of a single element: carbon, while other precious stones are a combination of two or more elements. Below you can see the cubic crystal structure of the diamond. Each carbon atom has a uniform stable covalent bond with the other four neighboring carbon atoms. 

Diamonds have the hardest surface known to science so far, considered to have grade 10, the maximum on the Mohs hardness scale. The only substance that can scratch a diamond is another diamond.


The basic criteria for evaluating diamonds, called "The 4 C's" are: Carat (weight), Color, Clarity, Cut. The four C system was established in the 1950s by the Gemological Institute of America (GIA) and is accepted as such by gemologists and businessmen.

 1. CARAT (weight)

The unit of measurement used by jewelers to measure diamonds is the carat.
One carat is equal to 0.20 grams. Often the weight of a diamond is measured in points. One carat equals 100 points. So a 0.75 carat diamond has 75 points. The carats of a diamond are actually a system for marking its weight. The name carat comes from the Greek word keration (which means carob). In the past, carob kernels, the uniform term of weight, was used to weigh precious stones. 

It is important to distinguish between carat (ct) as a unit of measurement for precious stones and Karat (K), a unit that measures the degree of fineness of precious metal alloys.


The color of the diamond has a significant impact on its value. The most common diamond color is transparent. There are also colored varieties such as: blue, orange, green, and sometimes it can be reddish, brown or black.

Diamond color scale according to GIA (Gemological Institute of America) standards:

D = the highest color grade of the diamond

E-F = almost colorless+

G = almost colorless

H = white (colorless)

I-J = colorless with slight tints of color

K = pale yellow

M, N-O, P, S-Z = colored


D is of course the best, rarest and most expensive color. Some diamonds enter the end zone of the color scale, towards Z (light yellow), but they are not special colors. Among the most available colors, most buyers opt for colors from D to J, according to the GIA system. Thus, D-E-F are the "colorless" grades, and G-H-I-J are the "almost colorless" grades.


The clarity of a diamond refers to the degree of impurities that a diamond can have when studied with the naked eye or with the help of a magnifying glass that magnifies 10 times. Only about 5% of the natural diamonds found are pure and at the same time have a size corresponding to a very good value. Specialists call these impurities "inclusions". The type, number and location of inclusions can often identify individual diamonds. The fewer impurities the diamond has, the more valuable it is.

Clarity standards:

FL (Flawless): No internal inclusions or external points. It represents the maximum level of clarity and corresponds to rare and very expensive diamonds

IF (Internally flawless): No internal inclusions but with possible tiny external imperfections

VVS-1 (Very Very Small inclusion 1): Usually it is about a single, small inclusion, visible with a 10x magnifying glass only by an expert eye.

VVS-2 (Very Very Small inclusion 2): The inclusions are very difficult to observe with a 10x magnifying glass.

VS (1-2)* (Very Slightly Imperfect): The inclusions can be seen with a 10x magnifying glass but not with the naked eye.

SI (1-2)* (Slightly Imperfect): The inclusions can be easily seen with a 10x magnifying glass.

I (1-2-3)* (Imperfect): Inclusions visible to the naked eye.


The cut indicates how the diamond is cut and gives it its shine. It refers to the proportions and finish of the diamond. Among the 4 C's, the cut is the only contribution made by the hand of man, transforming a rough, uncut gemstone into a faceted and polished diamond in various shapes. After thousands of experiments over the years, using precise mathematical formulas, today the diamond cutter-polisher transforms a rough diamond into a shining stone that reflects and refracts light.

Cutting into facets is a process by which part of the light falling on the flat surface of a very well polished facet is reflected like a mirror, highlighting the brilliance of the stone. Another part of the light that enters the diamond is refracted and reflected by the facets in its lower part, giving rise to the so-called "fires" of the stone.

The most famous and widespread diamond cut is the round brilliant. The classic diamond has 57 facets.


- Diamonds burn in an environment with pure oxygen at a temperature of 720 °C, and in air at over 800 °C with the formation of carbon dioxide.

- They are soluble in some metals such as iron, nickel, cobalt, chromium, titanium, platinum, palladium and other similar metals.

- Diamonds are considered the precious stone of those born in April and those born on Saturday

- The biggest diamond is not on earth but is a star 50 light years away with a diameter of 4000 Km and 10 billion trillion trillion carats!

Since ancient times, people have had a special attraction to diamonds, which were considered a symbol of perfection, invincibility and integrity. The brilliance of the diamond lasts over time due to its hardness and, along with its color, it can influence the nobility of the jewel. That's why diamonds were used to adorn different jewels (rings, earrings, pendants, royal crowns...).

They say that diamonds are a woman's best friend, so it's never too early to give new "friends" to the girls close to you.

There are several criteria for the appreciation of famous diamonds. One of them is the one that follows the size.

Thus, the largest diamond in the world is the Golden Jubilee. It has 545.67 carats and is the diamond that, after cutting, has the most faces. The Golden Jubilee was the gift given to the King of Thailand in 1997 by his subjects, 50 years after his coronation.

The Cullinan Diamond, believed to be the largest diamond ever discovered, was so astonishing in its size that when it was brought by a miner to the mine manager, he threw it out the window, saying that there could be no such thing as a diamond so big. This rough diamond had 3,106 carats, i.e. 602 grams, and was, in fact, only a part of an even larger diamond, detached after a cleavage face (cleavage - property of some minerals, rocks, crystals, etc. to unfold into sheets or plates with flat surfaces). The famous precious stone was discovered in the Premier mine (Transvaal), in South Africa, in 1905 and was named after the patron of the mine, Sir Thomas Cullinan. He was the general of a former British colony and offered the precious diamond to King Edvard VII - the 1st King of Great Britain, as a birthday present in 1907.

But the Cullinan Diamond was not preserved in its natural state, but was cut into 105 pieces - 9 large and 96 small, in Amsterdam. The largest polished diamond from the original stone is 530.2 carats and was considered the largest polished diamond in the world until 1985, when the Golden Jubilee diamond was discovered, also in the Premier mine, of 545.67 carats. The diamond is called Cullinan I, or the Great Star of Africa, and it was cut in the shape of a pear. He adorns the British royal scepter today.

 The second largest diamond, cut from the original stone, is called the Cullinan II, or Little Star of Africa, and is 317.40 carats, cushion-shaped, and located in the front, center of the Imperial State Crown of Great Britain.

The largest diamond in the United States and the third largest in the world is Incomparable. It has 407.48 carats and was cut from a stone that originally had 890 carats, i.e. 189 grams. After cutting, the main teardrop-shaped diamond and 14 other secondary stones resulted from the initial stone.

The largest black diamond in the world is called the Spirit of Grisogono and has 312.24 carats, being at the same time the fifth largest diamond in the world. It is set in white gold, set with white diamonds.

Centenary is the largest diamond in the world with clarity D. Clarity is one of the four criteria for the appreciation of diamonds, D being the maximum possible. The Centenary has 273.85 carats.

Tiffany Yellow is the largest yellow diamond in the world and has 128.54 carats. It was bought by the famous Tiffany house, in its raw form, cut and mounted in a brooch.

The most famous diamond in the world is the Koh-I-Noor. The diamond has 105 carats, the first attestation of it dating from 1304. The legend says that if worn by a man, the diamond attracts bad luck and death, but brings good luck if worn by a woman.

Ocean Dream is the only blue-green diamond in the world. It is only 5.51 carats but it is priceless, being the only known diamond with this color. The incredible color of the diamond formed a million years ago is the result of natural cosmic radiation.