Diamond Shapes

Asscher Cut
One of the most famous diamond magnates of the 19th century was Joseph Asscher, the genius cutter who became tied to not only a company and diamond shape that still bears his name. The Asscher-cut diamond was first introduced in 1902 and became the most sought-after style in the first half of the century.The Asscher cut is stepped, meaning that the reverse of the stone is carved like a staircase. This gives an Asscher-cut a "windmill" inside, as well as a "hall of mirrors" effect which sets strong white bars of light against black. The Art Deco history of this cut, along with its rectangular shape and cropped octagonal corners, makes this a gorgeous vintage choice.
Cushion Cut
Speaking of vintage cuts, it's impossible to overlook the cushion cut. Deriving its name from large facets and rounded corners, the cushion-cut diamond has been popular since the 19th century. Its ubiquity comes from its ability to be altered by creative diamantaires and its graceful, feminine appearance.Plus, the cushion-cut diamond has unique qualities all its own: It can capture even the slightest ray of light, which makes it a romantic diamond at candlelit dinners. And if you're a lover of colour, the same traits that allow the cushion-cut to capture light makes saturations of greens, pinks, yellows, and so on, show up more brilliantly. The cushion-cut diamond also hides a lot of inclusions, so you have more freedom when choosing your center stone.
Emerald Cut
Emerald-cut diamonds tend to be long rectangles, and with their beveled corners and step-cut facets, you may be reminded of an Asscher cut. The distinction comes from the extremely long surface table of the emerald-cut diamond. This is a plus when your diamond is internally flawless, since it shows off the purity of a diamond exceptionally well; but if there are inclusions, the broad face will show them off too. If you're a woman concerned with the way rings make her fingers look, an emerald-cut diamond may help. Long shapes like rectangles create the illusion of a slenderer finger!Marquise Cut
The marquise cut was first devised by France's King Louis XIV, who wanted a diamond to match the smile of his courtesan, the Marquise de Pompadour, for whom the cut was named. Rounded on both sides and coming to two points, the marquise cut is usually found as an accent (since it mimics the look of a leaf exceptionally well), but in modern times, it has made a comeback as a center stone for engagement rings. While the marquise-cut diamond makes for a gorgeous, one-of-a-kind choice for a center stone, it's crucial to pick a setting that will protect the delicate points and keep them from snagging on fabric. Aim for chevron-style prongs, halos, or bezel settings when shopping for a marquise-friendly ring.Oval Cut
You might be surprised to know that a shape as simple as the oval-cut isn't very old at all. The oval cut was invented in the early 1960s, designed to blend the best of round-cut and emerald-cut diamonds. Thanks to its numerous facets, the oval cut has nearly the same scintillation as a round cut, but its long length has the same "slendering" effect as an emerald-cut diamond.With oval-cut diamonds, the cut quality is more important than the other C's, because a poor cut ratio will exacerbate the "bow-tie effect" where internal light leaks from the center of the diamond, creating a black void at the heart of the stone. Oval-cut diamonds outside the ratio of 1.30 - 1.50 are at risk of suffering from this unsightly effect.