In the olden days the diamond business was entirely based on the personal evaluation by the jeweler. Generally jewelers used the criteria of colour, purity and size for evaluation of diamonds. Most of the time the buyer had absolute trust in the jeweler. As the diamond trade expanded, however, more and more members of the public were involved in the buying and selling of diamonds. Thus the confidence in old type of relationship ? the trust factor ? slowly began to reduce.

Laymen found it difficult to understand how the price of the diamond could be entirely dependant on the subjective opinion of a single individual or seller as each jeweler or diamond dealer seemed to have his own standard of judgment. Earlier days diamond were scarce. In the course of time diamond production started increasing. The world production of diamonds had recorded 6 million cts. in 1913 and by 1927, 8 million cts and as on today it is over 110 million cts. Therefore one of the established factors or rarity for value of the gemstones disappeared in the case of diamonds since it is produced in millions of carats. However of necessity, new rarity factors depending upon the colour and clarity of an individual stone emerged.
Inspite of the fact that diamond still serves as a symbol of love, constancy of success and power, the present day buyer is governed by the rational motive oriented towards the value of the diamond he purchases. Under the circumstances, it was necessary to evolve a more practical and consistent method for evaluation of diamonds. This is the main reason why during the 20th century the system for diamond grading developed, mainly emanating from USA, the largest consumer of diamond in the world today.
The present system of diamond grading is the result of an evolution that can be traced back almost 100 years.
Today the value of the diamond is determined by the popular dictum known as 4?C's which refer to the qualitative aspects such as clarity, colour, cut and carat weight. There exists large number of instruments, many especially designed, to enable graders to accurately judge the four qualities or characteristics.

Grading and classification of diamonds began in the beginning of the 20th century based on the internal features seen in a diamond as well as the colours of a diamond.
About 100 years back Paris was the most important trading center for diamonds. In order to differentiate the clean diamonds from those having inclusions, two designations were arrived at, "Pure" for cleans and "Pique" for spotted diamonds.
Around 1920, in USA the terms like VVS, VS, SI & 1 were coined to describe clarity grades.
Similarly colour grading is brought to be the oldest technique used for determination of a rarity grade systematically. Even before the discovery of the rich diamond deposits in South Africa a series of terms like Golcanda (for Indian origin), Bagagem (for Brazilian origin) were used to characterize the colour intensity of diamonds.
The various name of colours which originated from the then newly discovered sources in South Africa even today are still known as the old terms. For example "Jagar" for Jagersfontein mine. Jagar is equated with finest blue white.

In the year 1929 Robert Shipley having learnt gemmology at the Gemmological Association of Great Britain, established the Gernmological Institute of America in Los Angles in the year 1931, this started the GIA which established its own system of grading diamonds. As the diamond trade developed further, the early 1950's, the GIA started its first grading laboratory in New York to analyze individual stones and issue reports on their quality. These reports known as "grading certificates" can be recognized to be a major turning point in the diamond industry. It has changed the entire international diamond trade. As it was difficult to send diamonds for approval overseas, the diamond dealers found it very convenient to get the diamond graded, certified and mail only certificate. Only on the basis of the certificate people could buy the diamond without actually seeing it. To sum up it can be said that a certificate is a description of the identifying features of and the price determining factors associated with the diamond. As a rule it is prepared by the seller or is prepared for him by a Research Laboratory for delivering to the buyers as a statement in writing of certain properties.

The demand for diamond certificates grew rapidly as their authenticity was recognized. The CIA diamond grading system became well known to the diamond industry and amongst the consuming public. Originally the colours were described after their source. In the course of decades this system has been superseded by an alphabet system, in which the letter U represents the best colour quality ? River or exceptional white. The letters follow in an alphabetical order as far as ' Z '.

For clarity grading the CIA developed a the GIA clarity system which refers to both internal & external features of a cut diamond.

Grading of cut is of great importance and is carried out very precisely.

In Germany during the year 1935 the quality features were codified in the form of RAL, Agreement ? the German Standard Association's Commission on Terms of Delivery and safeguarding of quality.

In the year 1963, in the 5th edition of RAL the terms were defined for the first time. Subsequently the RAL regulations were replaced by the new CIBJO rules.

In the early seventies efforts were made to codify various national grading terms for diamond by an international uniform nomenclature. CIBJO is an International Association of the jewellery, silver, pearls and stones; CIBJO was formed in 1961 and today it is an Association of 21 countries which also includes India.

CIBJO consists of various sections of which a special Diamond Commission was formed in 1971. Diamond commission put forward rules for Diamond Trade in 1974, which were adopted as binding by CIBJO.

The Laboratories practicing CIBJO rules for Diamond Grading and Certification must be independent and impartial and should not involve in business of selling or buying diamonds.

CIBJO together with World Federation of Diamond Bourses, (WFDB) and International Diamond Manufacturers' Association (lDMA) founded a joint committee in 1975 with a view to workout international guidelines for judging the quality of Diamond. From this joint committee the IDC ? International Diamond Council emerged.

IDC's aim was to work out rules for the diamond trade which would be generally valid and consistent throughout the world. The international rules for grading diamonds were drawn up by IDC together with Diamond High Council (HRD) in Antwerp.

IDC in the meanwhile founded several Laboratories in which the work is carried out according to the International Rules for Diamond Grading. HRD in Antwerp, National Gemmological Institute in Israel, Diamond and Gemstone Testing Laboratory at the Diamond and Gemstone bourse in Idar Oberstein are working as per the IDC rules.

In 1969 the countries of Denmark, Finland, Norway and Sweden, under the chairmanship of H. Tillander of Helsinki, presented very detailed grading standards, which are summarized in the Scandinavian Nomenclature (Scan D.N.)Colour and clarity grading is in conformity with the GIA standards, here too external features are regarded as affecting the clarity. The colour terms are completely equivalent to those of the GIA.

Larger scope is given to the cut. Cut grading is simplified by means of a very well worked out point system. The proportions are based on those of the Scandinavian standard Brilliant, which were arrived at mathematically by TILLANDER.

The international norms have decided that the weight of diamond should be expressed in carats. In Certificate this figure should be confined to a hundred of a carat, i.e. to the 2nd decimal place.

In certificates the following' terms should be used as per IDC/CIBJO recommendations and not the old terms like River to yellow. Abbreviations are not permissible. Addition of the GIA colour grade of the GIA colour from D to Z in recent years became necessary as trade usage.

The Diamond colours are determined by the seven CIBJO master stones. The master stones describe the lower limit of each colour.

The colour grade of diamond is ascertained by comparing with CIBJO Master stones set using light source of 5500 Kelvin.

The above scale is internationally accepted as CIBJO/IDC Colour Grading Standard.

The colour grading scale is a descending scale which marks the lower limit, for eg. at a particular colour concentration, it is established as 'H' and above that level of colour till it reaches 'G' the colour is classified as H and then till F it is G and so on. In other words as F colour will not be designated as E till the time the shade crosses E. In this method the graders keep a strict check on the grading pattern. On the other hand, some of the private Laboratories have started issuing certificates of a higher grade as soon as the border line is crossed. In this manner a colour better than F on CIBJO or HRD standards may be classified by same individual grader as E. This results in upgradation of colour which is an unhealthy trade practice.

Colour specification must be made by experienced professionals, carried out by comparison to a master set chosen according to the original CIBJO master stones under normalized artificial light equivalent to 5500 K. If no difference observed between one of the master stones and the diamond to be graded, the colour of the master stone is conclusive. If the colour lies between those of the two master stones the colour of the darker one is conclusive. The fluorescence of the diamond has merely a descriptive value and is expressed as:

NONE - SLIGHT - MEDIUM - STRONG as seen under 366nm long Wave UV.

As colour comparison is not recommended in day light, because of its variable spectral colours, a suitable artificial day light source is essential.

Bright sun light is totally unsuitable as is the light of an electric bulb. Even the floors, carpets, walls and room furnishing should not be colored. A special diamond room should be maintained with gray colour and windows if possible, facing North in Northern hemisphere and to South in southern hemisphere. One of the best colour grading lamps available today is the Dialite models made by System Eickhorst.

The stones of comparison set are laid in a white folded paper on their table facets, so that the stone can be observed from the side of the pavilion sideways.

Diamond under test and the comparison stones should not touch each other.

Diamond should be cleaned thoroughly before colour grading as soiled diamonds can not be colour graded.

The international body, CIBJO, had laid down certain norms for puritylclarity grade. Accordingly to this all crystalline, solid inclusions, clouds, pinpoint fissures feathers, bearding, structural phenomena are termed as inclusions. The clar of a diamond is examined by an experienced professionals under 10x magnification.

External characteristics do not impair the clarity ? this applies to polishing lines, rough edges. Bum marks, ex located damages such as scratches, extra facets and naturals as well as twinning lines, growth lines and grain lines.
But major external characteristics which cannot be removed by repolishing without considerable loss of weight should be taken into account when grading for clarity.

Inclusions in a diamond have to be studied and defined in very clear terms. Broadly the study of inclusions for the purpose of clarity grading is grouped as under :-

As mentioned above clarity grading has to be done by 10x magnification only.

The size of inclusions is measured in microns. The diamond is termed "Loupe Clean" if it does not show any inclusions larger than 5 microns with 10x magnification.

However, it may be noted that stone cannot be graded if it is set in jewellery as the inclusions may be covered by the metal. The clarity grading has to be done by observing both the crown and pavilion portion of the diamond. Under the circumstances, it is misleading and hence unethical to make a statement, in a grading certificate, that the stone is "graded as mounting permits."

In general terms the cut of stone refer to its basic shape eg. Round brilliant cut, marquise and baguette cut etc. However for certification purposes, cut grading involves the analysis of the proportions and the finish of a diamond.

Until the beginning of this century, the forrns of diamond cut developed infinitely as men strove to obtain an optimal brilliance effect. It is this urge of people to strive for the best combination of brilliance and dispersion from a cut diamond that lead to the emergence of ideal cut. Since the year 1910 theoretical calculations have been employed to measure cut in order to obtain maximum brilliance through suitable proportions and symmetry ratios. As such, a series of proportion symmetry ratios were developed for cutting diamonds which were known as Ideal cut, Practical Fine cut, Parker brilliant, Scandinavian standard brilliant etc. depending on the individual preferences in different parts of the world. However, the most widely ?accepted proportions the world over as of today, are those known as "Tolkowsky Cut on the "American ideal cut" since it has optimum amount of brilliance and dispersion possible by means of optical physical calculations.

It is therefore very essential that the Diamond Grading Certificates should be obtained from an impartial and independent Trade Laboratory which follows the ethic and norms.

Given below are the International CIBJO approved laboratories :