london antwerp diamonds

London Antwerp Diamonds Ltd.
6, Laybourne House
Admirals Way
Canary Wharf
London E14 9UH

tel.: 0044(0)20 7193 6052



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Pavé | Pavilion | Pear Cut | Points | Polish | Princess Cut | Prong Setting

Radiant Cut | Ratio

Single-Cut | Shape | Step Cut | Symmetry

Table | Table Percentage | Tension Setting | Trilliant Cut


Pavé: a style of jewelry setting in which numerous small diamonds are mounted close together to create a glistening diamond crust that covers the whole piece of jewelry and obscures the metal beneath.

Pavilion: the lower portion of the diamond, below the girdle.

Pear Cut: a type of fancy shape diamond that resembles a teardrop.

Points: each carat in a diamond's weight is divided into 100 parts, called "points." A 1-Carat diamond has 100 points, a ¾ Carat has 75 points, etc. Points in a fraction of one carat are measured within ranges, so that a ¾ Carat diamond may have between .69 and .82 points and still be considered a ¾ carat.

Polish: refers to any blemishes on the surface of the diamond which are not significant enough to affect the clarity grade of the diamond. Examples are faint polishing lines and small surface nicks or scratches. Polish is as important as cut when grading diamonds. Polish grades are Ideal, Excellent, Very Good, Good, Fair or Poor.

Princess Cut: A type of brilliant cut fancy shape that can be either square or rectangular.

Prong Setting: the diamond is held in place by a number of metal prongs, which rise above the main body of the ring and are bent over the stone to hold it in place. The number of prongs and their height above the main body of the ring vary
according to the stone's shape.

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Radiant Cut: a type of brilliant cut fancy shape that resembles a square or rectangle with the corners cut off.

Ratio: a diamond is more long than wide and this ratio compares that relationship. In this ratio, width is always represented by the value '1'.To determine the value of the length, divide the millimeter measurement of the length by the millimeter measurement of the width. These millimeter measurements can be found at the top left-hand side of the diamond grading report. Length-to-width ratio is used to analyze the outline of fancy shapes only; it is never applied to round diamonds. There is no 'ideal' ratio; it's simply a matter of personal aesthetic preference.

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Single-Cut: a very small round diamond with only 16 or 17 facets, instead of the normal 57 or 58 facets of a full cut round brilliant. Single cuts are occasionally used for pavé jewelry and other jewelry that uses numerous small diamonds set closely together.

Shape: diamonds are available in seven shapes: round (also called brilliant or full-cut), marquise, pear, oval, princess, heart, pear and emerald. Which shape you choose is purely a matter of personal preference. Don't confuse a diamond's shape with its Cut, which is an evaluation of the diamond's proportions (and one of the 4C’s). Of course, the most popular and commonly seen shape for diamonds is the round or brilliant cut, which has 57 or 58 facets (depending on whether the culet, or point at the bottom of the stone, is faceted or not). It's the 'classic' shape that most people think of when they think of a diamond. Often considered the ideal shape for a diamond, the round cut was first perfected by a diamond cutter and mathematician named Marcel Tolkowsky, in his dissertation on the subject in 1919. Sometimes called the 'Father of the American Brilliant Cut',Tolkowsky was the first person to show that a diamond with 57 facets cut to specific proportions would result in the highest possible fire and brilliance. Over time, it became clear that it was not cost-effective to cut each and every diamond to these stringent requirements, since diamond weight was lost and the diamond apppeared smaller to the eye than a 'standard' cut of the same weight.

Step Cut: one of three styles of faceting arrangements. In this type of arrangement (named because its broad, flat planes resemble stair steps), there are three concentric rows of facets arranged around the table, and on the pavilion, there are three concentric rows arranged around the culet. Other styles of faceting arrangements include the brilliant cut (in which all facets radiate from the center of the diamond to its outer edges) and the mixed cut (in which either the crown or pavilion of a diamond is cut as a brilliant cut, and the other part of the diamond is cut as a step cut).

Symmetry: part of a diamond's overall finish, symmetry is critical to a diamond's value and its ability to refract light. In order to have good symmetry, a diamond's facets must be cut exactly to specific mathematical proportions. Symmetry describes several factors: how the facet edges align with each other; whether the corresponding facets from opposite sides of the diamond align with each other; and whether the facets from the crown, or top, of the diamond are properly aligned with the corresponding ones on the bottom (pavilion). When choosing a diamond that has been graded for symmetry, look for Good or Very Good ratings.

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Table: the flat facet on the top of the diamond. It is the largest facet on a cut diamond.

Table Percentage: a measurement of a diamond’s table width, relative to the width of the entire stone at its girdle, or widest point. This relationship is critical for maximum fire and brilliance: too small or too large a table can hamper the diamond's ability to disperse light properly and make it appear smaller for its weight. Table percentage is often indicated on diamond grading reports.

Tension Setting: this setting uses pressure to hold a stone between two open ends of the metal mounting, making the stone appear as if it's floating.

Trilliant Cut: a type of brilliant fancy shape that is triangular.

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