Bow Tie Effect
A ‘Bow Tie effect’ in diamonds appear as a black/grey or dark line or shadow running across diamonds on their narrow side. This can usually only be seen in diamonds when viewed ‘face up’. Diamonds that are typically asymmetrical in cut are susceptible to this unfortunate flaw, such as a Marquise, Oval, Heart and Pear.
Pictured is a Pear Cut Diamond with an obvious black/grey line running across the lower part of the stone. We would advise against this diamond!
Now you know what the ‘Bow Tie effect’ is, it’s best to try an avoid stones with a pronounced one. Of the cuts mentioned above most of them will have some form of ‘Bow Tie’ within them, its just a matter of minimizing it and finding the right cut. Stones of nearly identical proportions and cuts can vary with some displaying the ‘Bow Tie’ prominently while others will not. The most common of causes is in the cutting and the lack of precision on the facets. This in turn interferes with the refraction of light entering the diamond.
