What to Know

Fancy shaped lab diamonds, such as ovals, pears, marquises, and elongated radiants are among our most requested shapes. They're also the shapes where cut quality has the most visible impact on how a diamond actually looks in person.

Two of the most important factors to understand when shopping for a fancy shape are bow ties and light leakage. Neither appears on a grading report, and both exist on a spectrum rather than a simple pass/fail scale

What is a Bow Tie?

A bow tie is a darkened shadow that runs horizontally across the center of a fancy shaped diamond. In a well-cut diamond, all of the light that enters is reflected back through the facets, resulting in all the sparkle and fire that comes to mind when thinking of a diamond.

A bow-tie shaped shadow occurs when the facets in that area of the stone are angled in a way that directs light away from the viewer's eye rather than reflecting it back.

The important thing to understand is that bow ties are not a binary quality. Nearly every oval, pear, and marquise has some degree of bow tie, and a very subtle one can actually add dimension and character to a stone. The problem begins when the bow tie becomes large, dark, or persistent across multiple lighting conditions. At that point, it noticeably dulls the center of the diamond and is difficult to ignore once you see it.

Bow tie severity exists on a spectrum from barely perceptible to dramatic, and where a diamond falls on that spectrum is impossible to determine from a grading certificate or a standard 360 video. It can only be assessed by viewing the diamond in person, in a range of lighting conditions and angles. This is one of the primary reasons our team inspects every diamond in person before it enters our inventory.

What is Light Leakage?

Light leakage occurs when a diamond's pavilion facets (the lower half of the stone) are angled in a way that allows light to pass through rather than reflect back up through the crown. The result is a diamond that looks dull, lifeless, or washed out.

Like bow ties, light leakage is not all-or-nothing. Most diamonds have some minor degree of it, particularly around the edges, and a small amount is completely normal and acceptable. The issue arises when leakage is significant enough to visibly affect the diamond's brightness and overall light performance.

Step-cut shapes like emerald cuts, as well as elongated radiants in larger carat weights, can be more susceptible to light leakage due to their facet structure and depth. In these shapes especially, two stones with identical grades can look very different in person.