Diamond Glossary
Diamond Glossary
Plain definitions of the diamond and setting terms we use, each one linking to the full guide. Where a term is a trade name rather than an official gemological shape, we say so.
Dutch Marquise
A Dutch Marquise is an elongated hexagonal cut diamond: a long, narrow, six-sided outline whose straight angled sides meet in pointed ends. It tapers to a point at each end like a marquise, but its long sides are straight and angular rather than curved, so the silhouette reads as an elongated hexagon, not a smooth navette. Read the full guide.
Lab Grown Diamond
A Lab Grown Diamond is a real diamond. It is the same material as a mined diamond, pure crystallized carbon, with the same hardness (10 on the Mohs scale), graded as a diamond by the major labs (IGI and GCAL on the full 4Cs; GIA on its Premium and Standard descriptive tiers as of October 1, 2025; Source: GIA, 2025-10-01), and recognized as a diamond by the Federal Trade Commission (FTC Jewelry Guides, 2018). Read the full guide.
Oval cut
An oval cut is an elongated, symmetrical brilliant-cut diamond with a smooth, rounded outline and no corners or points. It uses the same fire-and-brightness faceting as a round brilliant, essentially stretched along one axis, so it keeps a round's sparkle while spreading that weight across a longer face-up shape. Read the full guide.
Emerald cut
An emerald cut is a rectangular step-cut diamond with cropped (beveled) corners and long, straight facets that run parallel to the edges of the stone. Instead of the small, fiery sparkle of a brilliant cut, those parallel facets act like a set of mirrors, producing broad, mirror-like flashes of light down an open, glassy table. Read the full guide.
Asscher cut
An asscher cut is a square step-cut diamond with cropped (beveled) corners and concentric square step facets that draw the eye straight down into the stone. Read the full guide.
Princess cut
A princess cut is a square (or near-square) brilliant cut diamond with sharp, uncropped corners and full brilliant faceting. In plain terms, it takes the bright, scintillating sparkle of a round brilliant and delivers it in a square outline with four crisp points, rather than a circle. Read the full guide.
Cushion cut
A cushion cut diamond is a square to rectangular brilliant cut with softly rounded corners, which gives it a pillow-shaped outline. That cushioned silhouette is where the name comes from. Its brilliant faceting returns light in broad, rounded flashes rather than sharp lines, so a cushion reads soft and romantic rather than crisp and icy. Read the full guide.
Elongated cushion cut
An elongated cushion is a cushion cut stretched to a longer, rectangular shape: a soft rectangle with gently curved sides and rounded, pillow-like corners, rather than the near-square of a classic cushion. Read the full guide.
Radiant cut
A radiant cut is a rectangular or square diamond with cropped corners and a brilliant facet pattern. It combines the straight-edged outline of an emerald cut with the fiery, scattered sparkle of a round brilliant, so you get a clean geometric shape that still lights up like a round. Read the full guide.
Pear shape
A pear shaped diamond, also called a teardrop, is a brilliant cut diamond with one rounded end and one pointed end. It combines the wide, rounded outline of a round brilliant with the taper of a marquise, so it reads as a smooth curve that narrows to a single point. Read the full guide.
Heart shape
A heart shaped diamond is a brilliant cut diamond with two rounded lobes at the top, a notch (the cleft) between them, and a single point at the base. Picture a pear shape with a cleft cut into its rounded end: the same soft curves running down the sides to a point, with the top split into two even lobes. Read the full guide.
Round brilliant
A round brilliant is the classic circular diamond, a perfectly round outline cut with 57 or 58 facets arranged to return the maximum amount of light to the eye. It's the most popular diamond shape and the most optically optimized: its faceting is engineered, down to the angles, to produce as much brilliance and fire as a diamond can. Read the full guide.
Marquise cut
A marquise diamond is an elongated cut with two gently curved sides that meet at two pointed ends, giving it a long, narrow, boat-like outline. Read the full guide.
Portuguese cut
A Portuguese cut is an antique-style brilliant with extra rows of facets: additional concentric rows of star and kite facets on both the crown and the pavilion, well beyond the 57 or 58 facets of a standard round brilliant, cut on a round or cushion outline. That dense faceting is the whole point of the cut. Read the full guide.
Rose cut
A rose cut diamond is an antique-style cut with a flat base and a domed crown of triangular facets that rise to a point, with no pavilion (the faceted lower half a modern diamond has). The name comes from the way the facets spiral like the petals of a rosebud. Read the full guide.
Old mine cut
An old mine cut is an antique, cushion-shaped diamond: a squarish outline with softly rounded corners, a tall crown, a small flat table on top, and an open culet, the tiny flat facet at the very bottom that reads as a small circle when you look straight down into the stone. Read the full guide.
Old European cut
An old European cut is an antique round diamond: a circular outline with a tall crown, a small flat table on top, and an open culet, the small flat facet at the bottom that reads as a tiny circle when you look straight down into the stone. Read the full guide.
Hexagon cut
A hexagon cut diamond is a six-sided diamond with a long, geometric outline. It can be faceted in different styles: a step cut, with clean parallel lines and an architectural look, or a brilliant style, for more sparkle. The six-sided outline is the shape; the faceting is a separate choice. Read the full guide.
Moval
A moval is a hybrid of two classic shapes, the marquise and the oval. It is an elongated diamond with the soft, rounded sides of an oval and the gently tapered, lightly pointed ends of a marquise. The name is just those two words combined: marquise plus oval. Read the full guide.
Hidden halo setting
A hidden halo is a ring of small diamonds set around the outer edge of the center stone's basket, just below the center diamond, so it sits out of sight from the top and shows only in the ring's side profile. Read the full guide.
Tulip setting
A tulip setting is a style of prong setting where the metal that holds the diamond flares up and outward in smooth, petal-like curves, so the head cradling the stone looks like an opening tulip. Read the full guide.
Tennis bracelet
A tennis bracelet is a flexible bracelet made of a single row of matched diamonds, each stone set in its own small link and joined edge to edge so the line bends smoothly around the wrist. There is no large centerpiece: the whole design is one continuous, even line of diamonds, which is why it is also called a line bracelet. Read the full guide.
Promise ring
A promise ring is a ring given to mark a serious commitment that isn't yet a formal engagement. It's worn as a visible sign of intent, exclusivity, or a personal promise between two people, and it carries whatever specific meaning the couple decides to give it. Read the full guide.
Bow-tie effect
The bow-tie effect is a darker band that runs across the center of an elongated diamond, shaped roughly like a bow tie. It is light physics, not a crack and not a defect. The shadow appears where facets in the middle of the stone return your own reflection instead of bouncing light back to your eye. Read the full guide.