The cut of a gemstone can make a world of difference. To understand this, all you need to do is compare pictures of a gemstone in rough form and after it is cut. High quality cutting maximizes the natural beauty of a gemstone and minimizes the visibility of flaws.
A well-cut gemstone should have good symmetry and proportions. However, the huge variation of gemstone colors means that, unlike white diamonds, there are no set standards for cutting.
Gemstones with very saturated colors will generally be cut shallower than gemstones with less saturated color. Deeper cuts can help to intensify the pale colors, while shallow cuts can help make the color of dark stones appear more vibrant.