Diamond Glossary

The knowledge and more information you have the better diamond purchase you will make. Here are a number of diamond terms that are used by jewelers to describe diamonds and which appear on diamond grading reports.

S:

Semi-mount:
A jewelry setting that has the side stones already mounted, but which contains an empty set of prongs which are intended to mount a diamond center stone that the customer selects separately.

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 utilizes numerous small diamonds set closely together.

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 out from the center of the diamond toward 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:
Refers to variations in a diamond's symmetry. The small variations can include misalignment of facets or facets that fail to point correctly to the girdle (this misalignment is completely undetectable to the naked eye). Symmetry is regarded as an indicator of the quality of as diamond's cut; it is graded as either Ideal, Excellent, Very Good, Good, Fair or Poor.

Shallow cut:
Cut refers to the angles and proportions a skilled craftsman creates in transforming a rough diamond into a finished diamond. When a diamond is cut too shallow, it will lose or leak light through the side or bottom. This results in less brilliance and value. Click here to learn more about cut.

Shape:
Shape refers to form or appearance of a diamond - i.e. whether the diamond is round, triangular, square, marquise, pear, oval or heart-shaped.

Saturation:
A color's position on a neutral to vivid scale.

Semi-mount:
A jewelry setting that has the side stones already mounted, but which contains an empty set of prongs which are intended to mount a diamond center stone that the customer selects separately.

Scratch:
A linear indentation normally seen as a fine white line, curved or straight.

Spread stone:
A Diamond with a large table and a thin crown height.

Surface Graining:
Surface indication of structural irregularity. May resemble faint facet junction lines, or cause a grooved or wavy surface, often cross facet junctions.

Scintillation:
The display of reflections from the polished facets of a gemstone seen by the observer when either the illuminant, the gemstone or the observer is in motion a flashing or twinkling of light from the facets.

Scratches:
Narrow, shallow, elongated, rough-edged depressions on the surface of a fashioned diamond, usually appearing as faint white lines under magnification.

Slightly Imperfect:
A grade of relative imperfection in a diamond. It signifies a more flawed condition than very slightly imperfect but less than imperfect. In general, stones are called “slightly imperfect” only if the flaws they contain are not visible face up to the unaided eye of a trained observer.

Slightly Yellow:
A diamond color grade that is used by some dealers for a stone showing an obvious yellow tint to the unaided eye.

Solitaire:
A term used to refer to a ring containing a single diamond or other gem.

Spread Stone:
A term that is used frequently in the diamond trade to refer to a stone that has been cut with a large table and a thin crown, to retain greater weight from the two sawn pieces of an octahedron than is possible by using ideal proportions. In a strict sense, any increase in table diameter over the ideal 53% constitutes spreading; however, it is a general trade practice to apply the term only to those stones with tables that measure in excess of about 60%.

Square Emerald Cut:
A form of step cutting with a square girdle outline but modified by corner facets.

Simulated Stones:
Any substance fashioned to imitate the appearance of a gemstone.

Star Facets:
The eight triangular facets that surround the table facet of a round, brilliant-cut diamond.

Synthetic:
A manmade gem material that has essentially the same physical, optical and chemical properties as that of its natural counterpart.

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