You are at : Site Map > Education and Guidance > Understanding Diamonds > Diamond Cut Diamond Cut The cut maximises the beauty of the stone. Diamonds are cut to ensure the maximum internal reflection so that they sparkle intensely. This sparkle is known as 'brilliance'. In order to achieve 'brilliance' each diamond is cut to ideal proportions. Its important not to confuse diamond cut with the outline shape of the stone itself. The following terms are used to describe the optical effects that are achieved through cutting a diamond. Total Internal Reflection This describes how light travels into and back out of a diamond above the girdle. Total Internal Reflection occurs when light enters a diamond, hits the internal facets and reflects out of the top of the stone equally. This happens because the facets of the stone are polished to the correct angles and ideal proportions. Brilliance Brilliance is the brightness of a diamond. It is the reflection of white light from the facets of the diamond.       Fire Fire describes the spectrum of coloured light reflected from within the stone, also known as 'dispersion'. Ideal Proportions The calculations for an ideally proportioned diamond of maximum brilliance were studied in great detail by Marcel Tolkowsky in the early 1900's. He established a series of measurements which act as a guideline to cutting a diamond of optimal brilliance. If the stone is too shallow or too deep then the light will leak out of the bottom or sides and the stone will lose brilliance. It is ideal to have a girdle which is balanced and 'medium'. 'Thick' girdles may use unnecessary weight .It is ideal to have a culet which is 'small', 'very small', 'medium' or 'none'. If the culet is 'large' or 'very large' it may be visible with the naked eye. Diamond Finish The finish is the term used to describe the aesthetic quality of a diamond based on the accuracy of cut and quality of polish. Diamond Polish The polish refers to the smoothness of the facets of the diamond once it has been cut. A shows polish lines from cutting process, blurring surface of diamond. B is an eye clean diamond with excellent polish.   Diamond Symmetry The symmetry of a diamond refers to the symmetry of the arrangement of the facets. A shows a diamond with excellent symmetry, exact shape and arrangement of facets. B is a diamond with misshapen facets. Anatomy of a Diamond To get a better understanding of the characteristic of cut it is helpful to know about the anatomy of a diamond. Diameter: The width of the diamond as measured through the girdle. Facet: The flat, smooth faces of a diamond, cut from the raw crystal. Table: The flat facet on the top of the diamond, it is the largest facet of a gemstone. Crown: The top portion of a diamond, from the girdle to the table. Girdle:The girdle is the outer edge of a diamond which forms a band around the stone between the crown and pavilion. Pavilion: The bottom part of a diamond, from the girdle to the culet. Culet: The culet is the smallest facet at the bottom of a full-cut diamond. All of the cut facets of the pavilion meet at a point to form the culet.  Depth: The height of a diamond, measured from the culet to the table. Diamond Cut Grading Table The following table displays the grades, comments and summary for diamond cut grading. Grade Comments Summary Excellent Thin / medium or slightly thick girdle. Finish is very good or excellent. Culet is either ‘none’, very small or small. Perfectly proportioned stones. Highest grades of polish and symmetry. Very Good Very Thin / Thin / medium / slightly thick or thick girdle. Finish is good. Culet is medium. Outstanding proportions maximising brilliance of diamond Good Very Thick or extremely thin girdle. Finish is fair. Culet is either slightly large or large. Good proportions ensuring good brilliance. Makes excellent quality jewellery. Fair Extremely thick girdle. Finish is fair. Culet is very large. Good proportions but not perfect. Lovence only offers for sale diamonds with the cut grades of 'Excellent' and 'Very Good', click here to read more about our diamond quality. [ Diamond Colour ] [ Diamond Clarity ] [ Diamond Cut ] [ Diamond Carat Weight ] [ Diamond Certification ] [ Diamond Shape ] [ Diamond Care ] [ Diamond FAQ ]