Nietemin, not all elongated shapes display bowties. The bowtie effect is a man-made problem and it happens during the cutting of the diamonds. Sometimes the bowtie is unavoidable because the diamond cutter has had to avoid another bigger problem in the stone and sometimes it’s simply the result of a mistake.
It’s easy to think that cutters should simply not cut bowties in their diamonds but diamond cutting is complicated work and even the best diamond cutters aren’t perfect. In short, here are the several main things that can result in a diamond bowtie:
A mistake – the cutter may have cut the diamond poorly with misaligned facets.
The cutter may feel forced to cut the diamond in such a way that it would result in a bowtie because the alternative is to cut too much rough off the diamond and reduce its carat weight excessively. At the end of the day, while every cutter wants to craft the most beautiful diamonds possible, this is a for-profit industry and the bigger the stone is, hoe beter.
The cutter may have had to cut the diamond this way in order to avoid bigger inclusions. Diamond bowties are unsightly, especially when they are very pronounced but they are not the worst thing that can happen to a diamond