In case a diamond has a poor cut, the light will not reflect properly from the gemstone. In many situations, this is caused due to leakage of light, but the obstruction of light causes the “bowtie effect”.
In place of light entering a diamond and existing elsewhere, the effect occurs when the light is shielded from entering the gem. Even though a diamond usually sparkles from all angles of the gem, the said effect results from the absence of light to begin with. The higher-quality cut, the less likely bowties will be visible. However, simply choosing a better cut diamond will not avoid the effect. Skilled gemstone cutters can reduce their appearance, but a diamond may appear to have bowtie for a different reason. An example is the polishing on fancy shaped or cut diamonds.
Polishing may get rid of carat weight from a rough diamond. This may cause even an expert diamond cutter to aim for a bowtie effect instead of creating a diamond that is smaller in size. Overall, higher quality cut results in reduced bowties, so you should pay heed to this especially when choosing a fancy diamond ring.