Table of Contents

Diamond Formation

  • The formation of diamonds began very early in the Earth's history, when the centre of the planet was subjected to incredible extremes of temperatures and pressure.
  • This heat pressure combined to cause the carbon atoms to crystallize forming diamonds and the intermittent volcanic eruptions brought the diamonds up to the surface.
  • Diamonds originate from two types of deposits - Primary deposits that consist of diamond-bearing pipes of a volcanic rock called Kimberlite. The secondary deposits, also referred to as alluvial, were formed as a result of erosion of material from primary deposits.




In selecting a diamond, the rarity, value and beauty is determined by the four factors mentioned here, called as:


The weight or size of a diamond is measured in carats (ct.). A carat is 0.2 grams and there are 100 points (or 200 milligrams) per carat. With an accuracy of 1/100,000 ct, the IGI scales provide a highly precise diamond weight and this weight is specified on the Diamond Report to two decimal points.

1 carat = 100 cents / 0.200gms / 200 milligram


0.075 - 0.02cts diamonds are known as ‘STAR’

0.02cts – 0.07cts diamonds are termed as ‘MELEE’

0.07- 0.13cts diamonds are termed as ‘+11 -14’

0.14 and above are termed as ‘Pointer’


Carat weight refers only to the weight of the diamonds and not to the dimensions of a diamond.


There is always a tolerance in the size of the diamond:

1/10 ct

0.10 cts

Can be .09 to 0.11 carat

1/8 ct

0.12 cts

Can be .12 to 0.13 carat

1/7 ct

0.14 cts

Can be .14 to 0.17 carat

1/5 ct

0.20 cts

Can be .18 to 0.22 carat

1/ 4 ct

0.25 cts

Can be .23 to 0.28 carat

1/ 3 ct

0.33 cts

Can be .29 to 0.36 carat

3/ 8 ct

0.37 cts

Can be .37 to 0.44 carat

1/ 2 ct

0.50 cts

Can be .45 to 0.58 carat

5/ 8 ct

0.62 cts

Can be .59 to 0.69 carat

3/ 4 ct

0.75 cts

Can be .70 to 0.79 carat

1 ct

1.00 cts

Can be .95 to 1.10 carat



  • Diamonds with few flaws, or inclusions, are very rare and highly valued. Clarity is graded based on the number, location, size, and type of the inclusions found in a diamond
  • The diamond clarity Grading is carried out using microscope and 10x loupe under the experienced eye of a gemologist.



  • The Cut is the factor that determines the brilliance of a diamond. A classic round brilliant cut diamond has 58 facets :
  • 33 on the top
  • 24 on the bottom
  • And the culet (1 point at the bottom).
  • Each of the diamond's facets must be placed in exact geometric relation to one another when the stone is being cut. Quality diamonds must be properly cut and not "spread", which means that the proper proportions are compromised to make the diamond weigh more.

Analyzing Cut

  • To understand the sub-categories for well-cut diamonds, think of a pyramid with "Ideal" at the top.
  • This narrow range is reserved for the most brilliant, rare and valuable diamonds. The "Excellent" range includes beautiful diamonds that return almost as much light. "Very Good" represents the balance between precise proportions and price considerations.


Effects Of Cut


  • Colour is the amount of body colour in the diamond. The clearer a diamond, the more value able it is. Colorless “D” on the color scale is the most value able because it has the most clarity. However, when a diamond is graded as a fancy colour, the value
  • increases due to the rarity of the Colour – sometimes refer as canary yellow diamonds.


1) Round Brilliant

The most common style of cutting both diamonds and colored stones. The standard round brilliant consists of 57 facets; 1 table, 8 bezel facets, 8 star facets 16 upper-girdle facets on the crown; 8 pavilion facets, 16 lower girdle facets; and usually a culet on the pavilion. Typical length-to-width ratio: 1 to 1.


2) Princess Cut

It is a relatively new shape and generally has 70 to 76 facets (no culet). The ideal princess cut diamond should be perfectly square with a length-to-width ratio between 1 and 1.05; whereas a more rectangular Princesses will have a length-to-width ratio greater than 1.10.
It often finds its way into solitaire engagement rings or earrings. This design is very well suited for long fingers and is often accompanied by triangular stones at its sides.

3) Pear

The pear shape is a brilliant cut, which means it has exactly 58 facets. This shape is reputed to be the crystallisation of a pure and perfect drop of water and is also referred to as a tear drop. The pear shape will often find its way on pendants or earrings. Common length-to-width ratio: 1.45 and 1.75.


4) Oval:

Longer than the round, this perfectly symmetrical shape will give the illusion of a larger diamond, as the shapes has a larger surface area than a round diamond with similar weight. Oval brilliant usually has 56 or 57 facets. Typical length-to-width ratio: 1 to 1.30-1.65.

5) Marquise

Inspired by the striking smile of the Marquise de Pompadour and custom made by the “Roi Soleil”, France's Louis XIV; the marquise cut is an elongated shape with pointed ends that was designed to match the Marquise’s eye catching smile. This shape is embedded with enough power to stand on its own and shine as a solitaire. The ideal marquise-cut diamonds should have length-to-width ratios between 1.75 and 2.25.

6) Radiant

This versatile design combines the brilliance of the round, the grace of the Emerald cut, and the panache of the Princess. Square shaped Radiants, should have a length-to-width ratio between 1 and 1.05. As for a more rectangular shape, the length-to-width ratio should be greater than 1.10.

7) Emerald:

The Emerald cut is an ideal design for fancy coloured diamonds. It’s shape is rectangular with cut corners and includes broad and flat planes that resemble stair steps when viewed from above. The crystal clear view which this shape has to offer may allow for inclusions and colour to be more pronounced. Hence, it is advised to select a stone of superior quality to fully profit from the smoothness of the Emerald cut. The classic emerald-cut shape will have a length-to-width ratio between 1.30 and 1.40.

8) Heart:

The ultimate symbol of love and romance. The heart shape is especially rare and sought after as a fancy pink diamond. The quality of this shape will depend to a great extent on the skill of the cutter. Furthermore, few diamonds are cut as hearts due to the complexity of the design, therefore heart shapes are currently undervalued from a rarity perspective.
The traditional heart-shaped diamond should have a length-to-width ratio between .90 and 1.10.

9) Cushion:

The last century’s oldest design (also known as "pillow-cut" diamonds) is available either in a square or rectangular shape, and includes rounded corners and larger facets to increase its brilliance.

For a square shaped cushion-cut diamond, the length-to-width ratio should be between 1 and 1.05. Alternatively, if you prefer a more rectangular shape, look for length-to-width ratios greater than 1.15.



Modern Brilliant Cut: Often known as the brilliant, round, round brilliant, or "brill.". It has 58 facets, including the table and culet. On this page we discuss the various parts of a round brilliant cut diamond, and the names of each part.


  • Crown Facets
    • Table
    • Star Facets
    • Kite or Bezel Facets
    • Upper girdle facets


  • Pavilion Facets
    • Main Pavilion Facets
    • Lower Girdle Facets
    • Culet

1) The Make : Table %

Table percentage is the ratio of the table width as compared to the total width of the diamond. For rounds, the largest diameter is used. For fancies, the smallest diameter (width as opposed to length) is used. For example, if the table measures 5.7 mm, and the total diameter of the diamond measures 10.0 mm, then the table percentage is 57%.

It is important to note that the trend toward smaller table percentages is a very recent phenomenon. Until the last 5 years or so, most people preferred a slightly larger table because it added width to the stone without sacrificing brilliance and only a miniscule bit of fire. Today, the trend toward "perfection" is creating a great demand for diamonds that are cut to so-called "ideal" proportions, increasing the price for Ideal Cut diamonds.


Ideal = 53 - 58%
Excellent = 58.1 - 60%
Good = 60.1 - 64%
Fair = 64 - 70%
Poor = over 70%

2) Diamond Girdle

The girdle is the outer edge of a diamond. It usually has a frosted appearance. Many diamonds are also finished with a fully polished or even a faceted girdle. This characteristic does not affect the value of a diamond and is often more a reflection the diamond cutter's preference. The girdle is rated in terms of thickness. Girdle size is generally defined as Extremely Thin, Very Thin, Thin, Medium, Slightly Thick, Thick, Very Thick, or Extremely Thick. The girdle can also be described as a range of these terms such as Thin to Thick. Avoid the two Extremes. When purchasing a diamond, select one with a girdle that is neither Extremely Thin nor Extremely Thick.


3) Culet

A diamond's culet is the point on the bottom of a diamond's pavilion. A diamond's culet may be pointed or it may be blunted with a small facet. The culet facet can vary in size. This culet's size determines the grade that the culet is assigned.

When searching for your diamond you should choose a diamond within this range:

  • Pointed
  • No culet
  • Very Small
  • Small
  • Medium

Below is the standard gemological laboratories' list of abbreviations used on diamond certifications that grade the condition of a diamond's culet.

N, NO, NON, - No Culet

P, PO, PN, PNT, - Pointed

VS, VSM, VRSM, - Very Small

S, SM, SML, - Small

M, ME, MD, MM, - Medium

L, LA, LG, - Large

VL, VLG, VRLG, - Very Large

EL, EX, EXLG, - Extremely Large



The pavilion is the bottom portion of the diamond, below the girdle. The height of the pavilion greatly contributes to the diamond's overall brilliance. If the pavillion is too long or too shallow in proportion to the rest of the diamond, light will "leak" out from the bottom of the stone resulting in a duller looking diamond.


5) The Crown

Upper part, or ‘top half’ of the diamond, above the girdle.

Angle measured between the girdle plane and the bezel facets. Crown angle together with table size determine how much fire (dispersion) and brilliance a diamond shows.


6) Diameter

For round brilliant cut diamonds, the measurements help you determine total symmetry. Perfectly round would mean more brilliance in a diamond. Though no diamond is quite perfectly round, you want to find one that is very close.

The first two figures in the measurements of a round are the maximum and minimum diameters. These two diameters should not vary by too much.

Example: A round diamond with measurements of 6.50 x 6.56 x 4.72. This means that the diameter varies by only 0.06 mm, which is quite acceptable for a 1-carat diamond as you will see in the following list.
Below are the opinions of Fire and Ice of acceptable variances for round brilliant diamonds in the popular sizes. Less variance is generally better.


7) Diameter

Carat Weight / Acceptable Variation

0.50 carat / 0.05 mm
0.60 carat / 0.06 mm
0.70 carat / 0.07 mm
0.80 carat / 0.08 mm
0.90 carat / 0.09 mm
1.00 carat / 0.10 mm
2.00 carat / 0.12 mm
3.00 carat / 0.14 mm
4.00 carat / 0.16 mm
5.00 carat / 0.17 mm

8) Depth

  • If you are interested in what makes a great looking diamond, it is important to consider the depth of the stone. Depending on the cut of the stone, the depth can vary. Depth not only can give the illusion of a bigger stone on a ring, the depth of the stone can also determine the amount of light that is reflected back to the eye. Here are some tips.
  • For many people buying a diamond, a larger surface area is an attractive way to give the illusion that the stone is much bigger than reality. Diamonds are extremely expensive and if a buyer can save a few thousand rupees while still getting a stone with lots of surface area, it might seem like a good idea.
  • It is important to note, however, that the way a diamond is cut, and specifically the depth of the diamond will determine the amount of light that is reflected back to the viewer’s eye. Too shallow a stone and the light will pass through it, too deep of a stone and the light is lost as well. If you want to get the most out of your diamond, the depth of the stone in the relation to the diameter should be 59.3%.


9) Fire

The quality of the diamond that breaks reflected light into a colorful array.


10) Brilliance

Of the four characteristics of a diamondthat contribute to its beauty , diamond brilliance is the most important. Brilliance is the life of the diamond . Brilliant diamonds explode with light, catching the eye, sparkling in candlelight, adding elegance and glamour to a woman's whole being. Diamond brilliance is what elicits the admiring glances from those around you.

A diamond can be big, it can have extraordinary colour, but if it isn't cut for maximum brilliance, fire and scintillation, then you have a dull and lifeless stone. Keep this in mind: diamond brilliance equates to beauty, so it contributes heavily to a diamond's value.

11) Diamond Fluorescence

Fluorescence is a characteristic that makes some diamonds appear to change color when they are exposed to the ultraviolet light that surrounds us every day in sunlight and in the light produced by fluorescent light bulbs Diamond grading reports also disclose the color produced by a diamond's fluorescence -- it's usually blue, yellow or white. A strong yellow fluorescence bring diamond prices down, sometimes quite a bit, since yellowish tinted diamonds are generally less desirable than whiter stones.

12) Natural

Usually found on the girdle. A small section was on the side of the raw diamond. It appears as a slightly rough flat spot on the girdle.



Various diamond setting styles are used in jewellery making. Here the settings of diamonds or the other stones such as Ruby, Sapphire etc are set on the jewellery.


  • Prong Setting
  • Pave Setting
  • Channel Setting
  • Pressure Setting
  • Flush Setting
  • Invisible Setting
  • Tension Setting
  • Bezel Setting



It consists of four or six claws that cradle the diamond. Because this setting allows the maximum amount of light to enter a stone from all angles, it sometimes can make a diamond appear larger and more brilliant than its actual weight. This setting can also hold larger diamonds more securely.



The diamonds are set on the metal with the help of grains which are pulled up from the metal and pushed against diamond. Has the look of precious gems paved across a piece of jewelry.



This setting is most frequently used for wedding and anniversary bands. A Channel setting will set the stones right next to each other with no metal separating them. The outer ridge of metal is then worked over the edges of the stones.

Tiffany : A six prong / four prong setting often round with prongs flare out to clamp the stones.


The Bezel setting is precisely crafted to embrace a gemstone and hold it securely in place. One of the oldest techniques used in gem-setting and remains an excellent method to protect both the girdle (middle) and pavilion (bottom) of a gemstone from chips and scratches.



This setting uses pressure to hold a stone between two open ends of a metal mounting, making the stone appear as if its floating.



A variant of the Bezel setting. In this variant, a window is cut into the base, the gem set into it and secured underneath.




Calibrated stones with slits are placed into a frame with ridges to hold them in place. No metal appears between any stones. This setting only employs baguettes and princess cuts or a combination of both.



The bar channel, a variation of the channel setting looks as if a number of stones float in adjacent berths with each stone docked in its own private channel and set apart from its neighbours by two thin metal bars.




Why Clean a Diamond ?


Diamonds have a tendency to develop a film build up of oils from lotions, powders, soaps, and natural skin oils which take away from their brilliance and sparkle. Chemicals in the air can slightly oxidize the mountings of precious jewellery depending on the karat grade used.


Diamonds should be cleaned so that the maximum amount of light can enter and return in a fiery brilliance. This will also ensure that the precious metal does not get dull or discolor. A

little time and effort on your part will keep your jewellery looking new like the day you first wore it.




1. Soak your diamond jewellery in a warm solution of mild liquid detergent and water.

2. Use a soft brush if necessary to remove dirt. Soft is the key - don't use a brush with bristles that are stiff enough to scratch the metal setting.

3. Swish the jewellery around in the solution, gently scrub away any residue or dirt, especially around the prongs or setting where build-up is common. Then rinse it thoroughly in warm water. Close the drain first, or put the Jewellery in a strainer to keep from losing it!

4. If the diamond and setting needs extra help, You can also use a wooden toothpick to very carefully push dirt away from the diamond and setting.

5. Dry the diamond jewellery with a lint-free cloth or with a selvet .

Note: Never use toothpaste or other abrasives to clean precious metal or gemstones.

Even a clean-looking diamond may have a layer of skin oil and will shine better after a cleaning. Avoid touching the diamond as much as possible to prevent that oil from building up.


The care you provide for your fine jewellery will reward you with years of pleasurable wear. Storing Your Diamonds with Care When you are not wearing diamonds and precious jewellery, they still require proper storage. Keep your precious pieces in a fabric-lined jewel case, or a box with compartments or dividers. If you cannot separate your jewellery in your jewellery box, wrap each piece individually in tissue paper or place in small plastic pouches. Don't jumble your diamond pieces in a drawer or jewellery case, because diamonds can scratch your other pieces of jewellery, or even scratch each other.


Travelling With Your Diamonds

The packing of your diamonds and other precious pieces for travel should be given care. There are many types of jewellery travelling carryalls available in the market, they come in all sizes, shapes and patterns; most have a velvet lining inside to attach pins and earrings, and compartments to place your bracelets and necklaces. To keep your jewellery looking it's best when you arrive, pack a small plastic bottle of prepared jewellery cleaner. Be sure you understand how your fine jewellery should be worn, how to store it, how to clean it, and what to look for to protect it from harm.