History of diamond and its marketing

Diamond would have been discovered in India, seven centuries ago before our era. They are thus the Indians who started to exploit it because it was for them a caste’ symbol. They used as well white diamond as color diamond.

It is with Pline the Older that the word diamond which comes from the Greek "adamas" took its significance of indestructible, untameable.

Then the exploitation of diamond continued in Borneo. It was necessary to wait the diamond’ discovery in Brazil in 1725 and South Africa in the years 1870 so that the marketing of this jewel will been accelerated until our days, where many mines were discovered everywhere in the world.

At the twentieth century,the Australia, China, Indonesia, Canada and Europe are recognized like producing areas of colourless and colors diamonds.

The diamond’ marketing began with the road from silk then with the discovery from the mines from Brazil, it became maritime with the creation of new diamonds centers which were especially harbour. Nowadays it is especially large capitals which became the great centers like Anvers, New York, Tel Aviv, London, Bombay or Bubaï.

The diamond value became during centuries a stable value because a true Financal market was founded.

There are various qualities of diamonds and so different types of markets: the crude market, industrial diamond (Boart) and the jewellery diamond.

It is in 1931, that the GIA (gemological institute of America) founded a nomenclature on its color (D to Z) and its purity (IF to P). And in 1970 that the certificate was obligatory.

PROPERTIES

It is a mineral of which the general formula chemical is made up of a single element carbon (C). The presence of elements traces, like nitrogen (N), boron (B) or again hydrogen (H), in its composition confers on the diamond all the colors of the light.

It crystallizes in the cubic system contrary to his « brother » the graphite (mine of pencil) which has the same chemical composition and crystallizes in the system hexagonal.

Diamond is the most hardest of natural and artificial materials with a hardness of 10 on the Mohs scale(qualificative scale to the stripe). It can be striped or polished only by itself.

This hardness comes from its mineral structure which has strong covalent bonds and also makes it possible to cleave it easily. It is thus hard but fragile.

The diamond has a relatively low density (d=3,52), lower for example than the density of sapphire (d=4). It is thus less heavy than sapphire.

The diamond is a very resistant material and the only product which can attack it is the potassium nitrate (KNO3) melted. Moreover it can burn in contact with the air at a higher temperature of approximately 850°C, of this fact the jewellers who works in coating it by Borax so that it does not become milky on its external layer when they heat it with the blowtorch.

The diamond has great optical properties, it is most transparent and has a particularly high index of refraction which gives him its "fires" and its brillance. The light is entirely reflects and dispersed in all the stone. It has a very low phosphorescence and sometimes it has a fluorescence under rays UV. This character is important because it can vary the promptness of the stone and thus its price.

The diamond is an excellent conducting thermics. when we touch it, it appears cold. But it is especially used like semiconductor. It is also an good electrical insulator except the black diamond (in functon of its rich presence of graphite). Finally the last property of the diamond is that it is hydrophobic (it cannot be wet) and lipophilic (it likes greases), thus to catch a diamond it is easier to use a little greasy object.

The various types of diamond

The color of diamonds come from to a defect in the structure of this one or by the presence of a foreign element.

1. either by a simple substitution of one of these atoms
2. either by a change of energy
3. either by accumulation of matter (aggregates or plates).

The classification of the diamonds is organized according to whether there is or no the presence of nitrogen in its structure. Two types then are distinguished :

1. type I: presence of nitrogen (N)
2. type II: absence of nitrogen (N)

We will summarize the classification of the colors in a table

Type	Definition	Color	Percentage
I a	Little group of azote with 0, 3% of azote	colorless, yellow, brown, pink green and blue	98 %
I b	Isolated azote with 0, 1% of azote	Intensive yellow, orange, brown and colorless	nearly 1 % seld
II a	Seld without azote	Colorless, brown, pink, purple, green and gilded	Nearly 0,8 % extremly seld exceptional white +
II b	without azote and 0,1% of bore (B)	Blue and grey	Nearly 0,2 % extremly seld

CARACTERISTICS

The evaluation of the quality of a diamond is estimated using an universally known method: "4C" (Carat, Color, Clarity, Cut).
A good comprehension of the "4C" allows to the purchaser to estimate the diamond with its right value. Any diamond must carefully be studied in order to draw essential information from them. Carat, Color, Clarity, Cut. The 4 criterias must have links which carry out on their respective descriptions. Any diamond must be, at the time of the purchasing, supplemented of a description of the "4C" by a recognized certificate.

CARAT

1carat = 1/5 G = 0.20 G = 100 points.
The carat is the universal measuring unit for the weight of a stone.
This word comes from caroubier, tree which has the property to have seeds whose weight is always equal and constant not to confuse carat of a stone and carat of gold alloys which are a percentage of gold.
This measuring unit was officialized in 1907.

COLOR

The color of a diamond was defined by alphabetical letters going from D to Z (D like Diamond) the letters A, B and C does not exist.
This colour gradation goes from the exceptional white + to the yellow clearly known as yellow course

D / E Exceptional white +	F Exceptional white	G Extra white	H White	I / J Moderate white	K / L Slightly white	M / Z Tinted

CLARITY

The purity in a diamond is an important criterion because it can vary considerably the price. The most beautiful and coveted stones and those which are limpid and pure, and thus extremely rare. To evaluate the purity, it is necessary to study the number and the position of inclusions. Inclusions are accidents of growth such as crystals, frost, of the veils or of the fractures.
A scale of purity was established in various degrees.

IF : Internal Flawless : pure in seeing with a magnifying glass, the diamond does not have inclusion under a lamp normal and examined with a magnifying glass 10X.
VVS : Very Very Small inclusion
VS : Very Small inclusions
SI : Small Inclusions
P1 : 1st Pique : inclusions that can be seeing without magnyfying glass
P2 : 2nd Pique : Large and many inclusions.
P3 : 3rd Pique : large and many inclusions affecting the brightness distinctly.

CUT

Normalizes established on the proportions of size of diamond which are expressed in percentages and in degrees on the basis of the percentage of 100% which corresponds to the diameter of a diamond, one determines: percentage height of the crown percentage depth of the cylinder head
The percentage thickness of rondist and in certain cases the percentage of the culet in degrees. It is the calculation of the slope of the crown and the slope of the cylinder head

Cut

Brilliant	Oval	Marquise	Pear	Heart	Emerald
Princess	Triangle	Baguette	Taper	Carré	8/8