The Princess Cut Diamond is a relatively new way to cut a diamond. It was first developed in 1964 as a way to provide a square diamond cut with facets equal to the round diamond cut known as a brilliant cut. Essentially it is a square version of a round brilliant. Its invention is credited to M. Weistreich, a Belgian diamond cutter also responsible for the development of the King Diamond Cut.
Prior to the development of the Princess Cut Diamond, square cuts of diamonds tended not to have multiple facets. These were called emerald cuts and they failed to take advantage of the additional sparkle that can be added when a diamond has numerous facets. Hence emerald cut diamonds were not preferable since they lacked the sparkly nature of round cuts.
One square cut prior to the Princess Cut Diamond did include extra faceting on the bottom of the diamond to open up the stone to more light penetration. This was called the profile cut. It has been suggested that the Princess Cut Diamond is really a variety of the profile cut.
However, the profile cut was still not as reflective or light producing as the Princess Cut Diamond would be. Thus diamond and jewelry manufacturers worked to develop a cut that would be ideal for certain settings requiring a square stone.
Some settings tend to be more attractive with a square diamond. For example the typical anniversary band called the eternity ring benefits from each diamond being a Princess Cut Diamond.
As well, certain diamonds in rough form are most ideal for shaping as a Princess Cut Diamond. In fact, the Princess Cut Diamond tends to be slightly less expensive because there are more rough diamonds to choose from for cutting purposes.
There are some rough stones that are not adaptable for Princess Cut Diamond styles. Shallow stones do not work particularly well. Another disadvantage of the Princess Cut Diamond is that the faceted corners on the top of the diamond may be slightly weaker if they are very thin, and may be more vulnerable to injury. Often jewelers will mount a Princess Cut Diamond in a way that protects the four corners of the stone to try to reduce damage to the points.