How Big Is a One Carat Princess Cut Diamond?

The princess cut is a style of cut used to preserve most of the original carat weight of the crystal. The shape is that of an upside-down pyramid, which is widest at the cutlet (the bottom of the diamond) and most narrow at the girdle, which is the part contained within a diamond's setting.

Identification

The princess-cut diamond is square, rather than rectangular or circular in shape, when viewed from the top of the setting. The edges are sharp, and corners are pointed and uncut.

Style

Most princess-cut diamonds use the "brilliant" style of cut, which uses a vertical crown with pavilion facets instead of the more traditional and older step-style cut with horizontal facets.

Dimensions

The crown height makes up about 10 to 15 percent of the total diamond. The length-to-width ratio is typically about 1:1 to 1.4:1, or less than 1.05.

Size

With the princess cut, a 1-carat diamond is approximately 6.5 mm in width, with a total depth equivalent to 65 to 75 percent of the total size of the diamond.

Benefits

This particular cut wastes little of the original size and dimension of the rough diamond, and the size of the crown is usually indicative of the largest area of the uncut stone. Nearly 60 to 80 percent of the rough diamond is used with the princess cut.

Resources

• Blue Nile: Diamond education
• Ajediam: Diamond size chart