What is the bow tie effect in diamonds? Oval cut diamonds
Similar to the marquise, oval cut diamonds can display a bow tie effect: a dark area shaped like a bow tie in the centre of the diamond. The bow tie effect appears in some fancy cut diamonds such as marquise, hearts and oval cut diamonds. The bow-tie effect is caused by imperfect proportions between the height, length and width of the rough diamond from which the stone is cut. Due to this imperfect structure,
light leaks through the diamond's pavilion, creating a dark shadow in the center of the diamond – from both girdles to the main belly facet. The effect creates an image that is similar to a bow tie, hence its name. The effect has varying levels, and is noticeable even without a magnifying glass. When it is very dark, the bow tie significantly damages the beauty of the cut diamond.
The Oval diamond one of the must popular diamond cuts nowadays is a beautiful brilliant cut diamond with a symmetrical elongated shape that gives an illusion of length on the hand, if worn on an engagement ring. It was created in the 1960s as an alternative to the round brilliant cut diamond.
The oval cut diamond is a brilliant and fiery diamond that reflects light beautifully. Like the round brilliant, it usually has 58 facets, but can vary slightly in its cut with anywhere from 4, 6 or 8 pavilion facets. There is no standard length to width ratio for oval cuts. They can be almost round, with a wider mid section and shorter length or very long and lean.
What does the term Hearts and Arrows mean?
When assessing the 'cut grade' of diamonds laboratories such as the GIA measure an average of the main facets on the crown and pavilion of the gemstone.
The term Hearts and Arrows comes from the pattern displayed on a perfectly cut fifty seven faceted Round Brilliant diamond which displays perfect internal optical symmetry when viewed under a specially designed light-directing viewer called a ‘Hearts and Arrows scope’. This viewer is a simple device that allows the analysis of the physical symmetry, contrast and alignment of facets of a diamond. It does this by viewing the stone through both the top (crown) and the bottom (pavilion) by directing white and coloured light at set angles in order to catch and reflect light back from specific facets and angles of the diamond. .
When viewed from the face up position the diamond displays a beautifully perfect pattern of eight symmetrical arrowheads and when viewed in the table-down position, shows eight perfectly symmetrical hearts. In these diamonds there is no difference in terms of the number of facets which means that every facet is cut to the same angle creating perfect optical symmetry.
Oval cut diamond rings are the perfect option for someone who loves the fire of the round brilliant diamond, but wants to have something a little bit different. Also, the elegant shape of the oval can look beautiful in a variety of jewellery pieces, from solitaire engagement rings to anniversary rings to pendants and earrings.
Picture: Bow Tie Effect © Reve Diamonds