How to choose a diamond: Cut

shutterstock_114395089How do I choose a diamond?  This a question that I get asked all the time.  My answer is always, start with the ‘cut’ of the stone.   I am referring here the quality of how a stone is cut (not the shape of the stone).

The quality of the cut is based on:

Proportions:diamond_cuts_chart the sizes and angles of various facets, which will affect the way light travels through a stone

Proportions are everything.   The better the proportions (measurements), the more light is returned out of the top of the stone and the more ‘brilliance’ (brightness) and ‘fire’ (sparkle) the stone will have.

If it is cut is:

  • too shallow, light leaks out of the bottom
  • too deep, it escapes out of the back facets
  • Perfect when the stones returns the maximum ammout of light




Symmetry: the symmetrical appearance of the stone

For example, in a brilliant round stone, you will want a stone where

  • the stone outline is round (when viewed from above)
  • the culet (point at bottom of stone) is in the centre
  • the table (top of stone) is symmetrical and in centre of stone
  • the girdle (the outer edge of the stone) remains at an even distance from the table all the way around



The quality of the polish is affected by:

  • polishing line – parallel lines on the surface of the stone produced when polishing
  • Burn marks caused by poor polishing
  • A good stone will have little or no polish imperfections that can be seen even under 10x magnification


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