Wednesday, 23 May 2012

Diamond Symmetry - Chennai Diamond Rhino Jewel Gold Studded Jewellery Designing CAD WAX Casting Institute Courses Training Tamil Nadu India


AESERA  Jewellery DESIGNING ACADEMY

No 144/74, Eskay building, 3rd floor,
Greams Road, Thousand Lights
Chennai,  Tamil Nadu
India,
Mobile: +91-9444100081,+91-9840689781,+91-9840966467

seshu.gopal@jewelrydesignacademy.com

WHEN A FACETED DIAMOND IS OBSERVED UNDER NORMAL LOX MAGNIFICATION ONE CAN EASILY STUDY THE SYMMETRY ASPECTS OF THE CUT. TODAY THE SYMMETRY OF A FACETED DIAMOND PLAYS A SUBSTANTIAL ROLE IN THE CUT EVALUATION OF DIAMONDS.

There are certain factors that have to be checked for the perfect cut grade and these are:

Symmetry of table and table edges1. Symmetry of the sides of the table edges
The table facet of the round brilliant cut should form a perfect octagonal shape, sometimes one or more blunt table edges are observed. There should be four sets of parallel sides of the octagonal shaped table. When the edges are not straight, but are wavy then a good symmetrical cut is ruled out.

2. Centricity and parallelism of table
Excentric tableThe table facet has to be parallel to the girdle plane so that the crown height is equal in all directions. Many a time the table is tilted to remove some inclusion near the surface of the table. The octagonal shape of the table should have its centre exactly above the culet, otherwise it is called eccentric. An eccentric table creates different sizes of crown facets which affects the brilliance of the diamond.


3. Centricity of the culet
Excentric culetThe fine point or the smallest facet at the base of the brilliant cut is the culet. Sometimes the culet is faceted. This culet should lie in the centre of the octagonal table. It is very easy to see whether the culet is eccentric from a side view of the stone as well as on looking through the table. If the culet is eccentric then it indicates that the pavilion facet angles are unequal. This gives a very adverse effect on the reflection of light symmetry.


4. Sharpness in the intersection of the facet edges
Truncated facetsIn a perfect cut the edges of individual facets must meet in a single intersection without any truncated ends. Truncated facets do not meet at a point and affect the uniformity of the cut. Thus a truncated main facet when observed through the table interrupts the symmetrical effect of the adjoining facets.


5. Alignment of the crown and the pavilion facets
Displacements of the crown and pavilon facetsThe kite facets of the crown should exactly intersect with the pointed edge of the pavilion main facet and the upper girdle facet should synchronise with t\\t \owcv girdYe facets. There should be a perfect alignment and no sideways displacement with respect to each other. As this clearly affects the regularity of the cut and gives rise to uneven girdle as well as reduced brilliance.




Diamond Polish

EXTERNAL FEATURES THAT SHOULD BE NOTED ARE POLISH, SURFACE BLEMISHES & EXTRA FACETS.

The polish of a diamond shows how well the diamond was finished, how clean , shinny and straight edged the facets where cut, if any traces of minute or microscopic lines or blemishes were left by the polisher plus whether any marks are visible on the stone. A well polished diamond is more brilliant than a poorly polished diamond. Other marks can also be scratches or tiny chips, diamonds may be damaged if roughly handled together.


Well polished diamonds
Polish terminology as seen on grading certificates:
  • P = Poor
  • F = Fair
  • G or GO or GD = Good
  • VG or VE = Very Good
  • E or X or EX = Excellent

Diamond Fluorescence


FLUORESCENCE IN DIAMONDS, SOME PEOPLE LIKE THE EFFECT WHILE OTHERS DO NOT, IN USUAL CIRCUMSTANCES IT IS NEVER SEEN UNLESS THE DIAMOND DISPLAYS A VERY HIGH FLUORESCENCE, THOUGH IF A DIAMOND THAT DISPLAYS USUAL FLUORESCENCE IS EXPOSED TO DIRECT OR INTENSE ULTRAVIOLET LIGHT A BLUISH GLOW CAN BE OBSERVED. STRONG FLUORESCENCE CAN LOWER THE PRICE OF A DIAMOND, BUT IN SOME CASE MAY EVEN LIFT THE COLOR ONE GRADE TO THE NAKED EYE SO TO ADD TO THE BEAUTY, OR EVEN DETRACT FROM THE DIAMOND GIVING IT A SLIGHTLY HAZY APPEARANCE. IT'S ONE FACTOR THAT SHOULD BE CHECK WITH THE INDIVIDUAL OPINION DEPENDING ON THE AMOUNT OF FLUORESCENCE DISPLAYED.



Diamonds displaying different levels of fluorescence under ultraviolet light
Listed below are the abbreviations for describing strength of fluorescence that should be noted when reading a diamond grading report:
Strong Fluorescence
  • N, NO, NON, - No Fluorescence
  • F, FB, FT, FA, - Faint or Faint Blue Fluorescence
  • SL, SLB, SLT, - Slight Fluorescence
  • M, MO, ME, MD - Medium or Moderate Fluorescence
  • S, ST, STB, STG, - Strong Fluorescence
  • E, EX, EXB, EF, - Extreme Fluorescence

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