Friday 9 August 2013

A Diamond’s Table Size

A Diamond’s Table Size


The table of the diamond is the largest facet of the diamond; the flat top surface of the diamond.



The Table % of the diamond is calculated by dividing the width of the table by the diameter of the diamond (taken from each end of the girdle) multiply by 100.
Example: 3.5mm table / 6mm width table x 100 = 58%

The size of the table may affect a diamond's beauty in different aspects:

Spread

Diamonds with a larger table will appear bigger than diamonds with a smaller table, hence having a larger spread.

Fire

A diamond with a smaller table has more fire as there is a larger surface area of the crown facet area, where more light enters and exists at a critical angle, causing more dispersion of light.

Brightness

Diamonds with a larger table appear brighter. This is due to the contrast differences in the diamond. A smaller table appears to have thicker arrows of contrast, leaving the diamond to be less bright. A diamond with a larger table has smaller sized arrows of contrast, leaving more space of brighter areas (more light return), resulting in a brighter diamond.







Scintillation

Diamonds with a smaller table produces a higher amount of scintillation. Since there is more interplay between the crown and the pavillion facets, we will see more patterned scintillation and sparkle scintillation.

Diamonds with a larger table produces a lower amount of scintillation due to the lack of interplay between the crown and the pavillion facets, we will see less patterned and sparkle scintillation.






SUMMARY



Small table:

+ fire

+ sparkle scintillation
+ patterned scintillation
- spread
- brightness

Large table:
+ spread
+ brightness
- fire
- sparkle scintillation
- patterned scintillation
*danger of fish eye effect





CONCLUSION

With all this in mind, what kind of table diameter should I go for?

The ideal range would be 53-58%.

Diamonds are all about finding the perfect balance of brightness, contrast, fire, scintillation and spread. However, a diamond with a larger table appears to have more CON's than PRO's. When the table reaches too high a level, light leakage is apparent under the table. When a ring is worn, dust and dirt may be seen right through the table, leaving the diamond appearing even less bright than it should.

When picking a diamond in the ideal range of 53-58, look to the other angles and minor facets such as the stars and lower halves, these would start to have a higher impact of how a diamond is performing.