Asscher Cut Diamond Buying Guide
Shape
Asscher is a square shape with a 'step cut' pattern and cropped corners. Due to its form, a visual phenomen which resembles an 'X' symbol can be seen in a table-up view. More formal name for an asscher shape is 'square emerald', since both these shapes include a pattern of steps going from sides to the center of the diamond.
Cut
Asscher is in fact an octagonal because of its cropped corners, however the shape should be as symmetrical as a square to look good. This is why the go-to length to width ratio needs to be in the range from 1.00 to 1.10. The diamond's table is flat, which gives a gemstone more of a glass-like appearance. The intensity of light play depends on the numbers of facets.

There are basically two types of asscher diamonds: Original Asscher cut and Royal Asscher cut. Original Asscher cut has straight edges and 58 facets which are usually wider than the facets of an emerald diamond. While these features allow for an original look, the gemstone doesn't excibit a lot of brilliance.

Royal Asscher cut is defined by a bigger crown and 74 facets which allow for a much better light performance.
Excellent | Very Good | Good | Fair | Poor | |
Table % | 61% - 69% | 57% - 60% or 70% - 72% | 54% - 56% or 73% - 74% | 51% - 53% or 75% - 79% | < 51% or > 79% |
Depth % | 61% - 67% | 69% - 60.9% or 67.1% - 70% | 57% - 58.9% or 70.1% - 74% | 54% - 56.9% or 74.1% - 79% | < 54% or > 79% |
Girdle | Very Thin to Slightly Thick | Very Thin to Thick | Very Thin to Very Thick | Extremely Thin or Extremely Thick | |
Culet | None | Very Small | Small | Medium | > Medium |

Clarity
When it comes to the clarity characteristics, asscher diamonds are not very good at hiding the imperfections. Open window-like facets and large table allow for most of the inclusions to be visible even to a naked eye. This is why going for a higher clarity grade in a gemstone is a better choice. Settling for something lower than VS1 is not recommended to make sure that nobody will see the flaws in the diamond.

Color
Asscher cut is not as good at hiding yellowish or gray tints as an emerald. However, the ideally colorless gemstone might look more glass-like than anyone would want. The perfect compromise for asscher shape is F or G color grade. Something that is graded higher, or lower, might not have that desirable appearance of clean and sparkly, but still slightly warm diamond.