Shape is one factor in a diamond’s price. Some shapes are more difficult to produce than others. Part of the rough diamond is wasted when cutting and polishing diamond stones.
The round (also known as brilliant) is by far the most popular diamond shape, accounting for more than 75% of all diamonds sold. Consumer tastes vary with fashion, often driven by celebrities or T.V. shows, but most people want their diamonds to be classics – outlasting fads or shifting fashions.
Princess cut (also known as square modified brilliant) – the second most popular shape, which accentuates diamond’s fire and brilliance rather than its luster. The Princess cuts are typically less expensive per carat than round brilliants because cutters do not have to cut off as much material from the rough diamond.
Emerald this is a rectangular shaped diamond with a larger, open table (table is the top of a diamond). Because of the large square of the table, the color of this diamond is more noticeable and hence should be chosen more carefully. Typically, anything in the range of K to Z grade will be visibly too yellowish.
Asscher This 72-faceted diamond was designed in 1902 by Joseph Asscher, a diamond jeweler from Amsterdam. The Asscher is a square version of the rectangular emerald cut. This shape has regained some of its popularity in recent years, thanks to being featured on Sex and the City and by some celebrities.
Marquise (also known as navette or little boat in French) – this diamond, shaped like the hull of a boat. Marquise diamond shape makes the diamond look bigger than it actually is and also makes fingers wearing this diamond look longer and more slender. When buying the diamond of this shape, watch out for the bow tie effect (i.e. the diamond’s markedly dark center) if it is cut too thin. The depth of this diamond should not be less than 60%