Diamond Designs and More

Diamonds

 

Image of a diamond A diamond is the hardest substance on earth with unique powers of light reflection. Its name originates from the Greek word "adamas" which means "unconquerable". Since ancient Greece, diamonds have been the traditional symbol of love, and adamas could also indicate the eternity of love.

Diamonds are a very high density carbon crystal structure which were created under high pressure 300 kilometres under the earth’s surface and were carried to the surface through various movements in the outer mantel of the earth. In terms of hardness, diamonds are about 140 times harder than the second hardest minerals on earth, the corunds (rubies and sapphires). Despite its hardness, due to its chrystaline structure, diamonds are susceptible to hard blows, and may chip clean along its facets which represents the basis for cutting and shaping diamonds.

The value of a diamond depends on four factors, generally referred to as the Diamond’s 4-C’s.

Cut


Cut refers to two features in understanding diamonds: brilliance quality and shape. more...

Clarity


Clarity is a measure of the amount of inclusions or imperfects exist in a diamond crystal. The fewer the inclusions, the clearer, more brilliant and more expensive a diamond is. Each cut and polished jewel diamond, no matter how small in size, has been professionally graded. The inclusions may consist of other minerals trapped within the diamond crystal or imperfections as a result of cracks in the crystal structure or other inconsisties in the crystal structure which originated during its creation. more...

Color


Diamonds are available in all colours. Among the colorless group of diamonds, the most frequent are the yellow tones. The more colorless a diamond is, the more valuable it becomes. To the naked eye, most diamonds appear colorless, however these diamonds may contain slight traces of yellow or light brown. These colorless diamonds are graded from D to Z. more...

Carat Weight


Carat weight refers to the actual weight of the diamond. Carat weight of a diamond is almost meaningless unless quality of cut, clarity and color are considered. more...


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Brilliance Quality


Cross section cut of a diamondThe cut is the most important characteristic of a diamond. The beauty of a diamond, and hence its brilliance is decided by its cut. The cut determines how much of the light that penetrates into a diamond from the top will be reflected back to the eye of the observer via its appropriately angled mirror facets around the bottom of the diamond. A skilled diamond cutter will cut a raw diamond stone in such a way that its facets are in exact geometric relation to one another.
Diamond features
The ideal cut diamond is one which maximizes the amount of light that enters a diamond to be reflected back to the eye of the observer. The esthetic value of a poorly cut stone will be much diminished even if that stone has high grades in the other three C’s. A poorly cut diamond can result from one of three factors:

1) the facets are not in exact geometric relation to one another,
2) the cut is too shallow or
3) the cut is too deep.

The latter two result in the light "leaking" out through its bottom facets rather than being reflected back to the observer.

Image of a shallow cut diamond Image of a ideal cut diamond Image of a deep cut diamond

While symmetry, angles and depth percentage of a diamond are important factors in determining the quality of a cut, there are other factors too that play a role: table width percentage, crown angles, crown height, girdle thickness, pavillion depth, culet size, finish and polish.
For large diamonds of 1.0 carat size or larger, a Certificate by the Institute of Gemnology will provide all the technical details about an analysed diamond’s cut qualities versus the ideal cut, however for smaller diamonds such Certificates which cost around $250 per analysed diamond are not provided by the diamond merchant.

Shape


Another feature of cut, which however is not quality related, is shape. There are a number of classic shapes for diamonds which include:

Image of diamond tables Image of measurement of the diamond table

a) the brilliant cut diamond (only round diamonds with at least 32 upper facets, 24 lower facets, 1 table platform at the top, and one culet platform at the bottom may be called "brilliant cut" diamonds)

Different shapes of diamonds b) other multi-faceted diamonds: oval shape, pear shape, marquise shape, heart shape, emerald shape, baguette shape, trilliant triangle shape, radiant shape


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Clarity Grading Scale

GIA  Definition CIBJO  German
FL

flawless
no internal inclusions are visible under 10x magnification    
IF

internally flawless
no internal inclusions are visible under 10x magnification, but minor surface blemishes exist that do not penetrate the stone Lr Lupenrein
Example of a FL-IF clarity
VVS 1
VVS 2

very very small inclusions
extremely small inclusions which are hardly visible under 10 x magnification VVS sehr sehr kleine Einschlüsse
Example of a VVS 1-2 clarity
VS 1
VS 2


very small inclusions
very small inclusions which are difficult to observe under 10 x magnification VS sehr kleine Einschlüsse
Example of a VS 1-2 clarity
SI 1
SI 2

small inclusions
small inclusions which are obvious under 10x magnification, but are difficult to see with the unaided eye SI kleine Einschlüsse
Example of a S 1-2 clarity
I 1

imperfections 1
off centre inclusions which are easy to locate under 10x magnification, and obvious to a gemologist with his naked eye P I Pikee I
Example of a L 1 clarity
I 2

imperfections 2 
centrally located inclusions which are easy to locate under 10x magnification, and are obvious to a gemologist with his naked eye P II Pikee II
I 3

imperfections 3 
blemishes and inclusions eas to locate with the naked eye P III Pikee III
Example of a I 2-3 clarity

 

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Color Grades

GIA CIBJO / IDC Old Terms
D colorless exceptional white river
E exceptional white river
F rare white top wesselton
G Near colorless rare white top wesselton
H white wesselton
I slightly tinted white top chrystal
J slightly tinted white top chrystal
K faint yellow tinted white chrystal
L tinted white chrystal
M tinted color top cape
N - R very light yellow tinted color cape light yellow
S - Z light yellow tinted color yellow
Chart of diamond colors

 

Fancy Diamonds


Examples of fancy diamonds In nature, diamonds can also occur in shades of deep yellow, red, pink, blue or green. They are known as "Fancy Diamonds", and can be quite valuable.


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Carat Weight


The standard measure of a diamond’s size is Carat (ct) weight. Carat means weight. 1 carat = 1/5 of a gram. The one carat weight is further broken down into 100 equal parts called "points". Hence a quarter carat diamond is equivalent to a 25 pt diamond.
Carat weight of a diamond is almost meaningless unless quality of cut, clarity and color are considered. A large one carat diamond is not very valuable if it lacks brilliance, clarity and high grade color. However, if a diamond meets the high standards of each of the other 3 C’s, then each point of carat weight progressively adds to price increase. Due to the rarity of increasingly larger diamonds, a 50 point diamond is much more than two times the price of a 25 point diamond.
The most standard cut for a diamond is the Brilliant Round Cut. For this type of cut/shape, a weight scale helps to determine the largest diameter (in millimeter – mm) of the diamond when looking at it from the top in relation to its carat weight.


Top View Measurements of
Brilliant Round Cut Diamond

Weight
(in Carat)  
Diameter
(in mm)
  Weight
(in Carat)  
Diameter
(in mm)
0.01 1.50   0.15 3.40
0.02 1.75   0.20 3.80
0.03 2.00   0.25 4.10
0.04 2.20   0.33 4.40
0.05 2.50   0.40 4.80
0.06 2.60   0.50 5.20
0.07 2.70   0.75 5.90
0.08 2.80   1.00 6.50
0.09 2.90   1.50 7.40
0.10 3.00   2.00 8.20

 

 
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