The Emerald Cut
The emerald cut is the only cut named for a gemstone. It began with the introduction of emeralds from Colombia by the Spanish conquers in the 15th century. Instead of the historic tablet cut, basically flat cut almost like a thick window pane, the emerald cut was developed. In place of a flat bottom, angled facets were added (called the pavilion). It was discovered that these angled facets needed to be somewhat steep as a less sheer angle would lower an emerald's intensity and add a see-through effect called "windowing."
Since the crystals are hexagonal - an elongated six-sided crystal with flat terminations at each end - the emerald cut served to retain maximum weight from these rare and expensive gems in addition to intensifying color - both factors which increased their value.
Colombian emeralds tended to have the most of the "emerald" color concentrated in the ends (terminations) and along the six sides in what can be described as a rind. Cutters soon learned to fashion the gemstone to include this rind. That process deepened the emerald's color. Although the number of pavilion steps can vary in number, each additional step helps to deepen the emerald's color, thus the prevailing number is three to five facets.
The emerald cut revolution had an influence on diamonds cutters in a future century when diamond cutters utilized reflective facets on the pavilion to bring out a diamond's beauty.
