Glossary of Terms
| Blemish: | A flaw (scratch or abrasion) on the surface of a diamond. |
| Brilliance: | White light reflected up from the surface of a diamond. Brilliance is maximized by cutting a diamond to the correct proportions. |
| Brilliant Cut: | A 58-facet round diamond. |
| Carat: | A unit of weight for a diamond, equivalent to 200 milligrams, or one fifth of a gram. |
| Clarity: | A grade given to a diamond to describe how many inclusions the diamond has. The clarity scale ranges from FL (flawless), meaning a diamond has no internal or external flaws, to I3 (severely included), meaning a diamond has many flaws clearly visible to the naked eye. |
| Cloud: | A cluster of small inclusions inside a diamond. |
| Color: | A grade given to a diamond to describe the color tones of the stone. The color scale ranges from D, meaning completely colorless, to Z, fancy yellow. As the scale moves from D to Z, it indicates increasing levels of yellow and brown tone. |
| Culet: | A facet on the very bottom of a diamond. If the culet is medium to large, when the diamond is viewed from the table, it will look like there is a hole in the bottom of the stone. |
| Cut: | Commonly used to refer to both the shape of a stone (round, pear, oval, etc.) and the make (the exact geometric proportions to which a diamond is cut). The make of a stone is the most important factor in determining how much sparkle comes from a diamond. |
| Ideal Cut: | Round diamonds that are perfectly proportioned (having depth percentages and table percentages that maximize fire and brilliance) and have high grades on polish and symmetry. These stones have had the finest craftsmanship to maximize the beauty of the diamond. |
| Very Good Cut: | Diamonds cut to fit very strict requirements for depth percentage and table percentage. These outstanding proportions maximize fire and brilliance in the diamond. |
| Good Cut: | Diamonds cut with acceptable, but not perfect, cut proportions. They generally have very good brilliance and fire and make excellent jewelry. |
| Fair Cut: | Diamonds cut to less perfect proportions. They have been cut to maximize the weight of the stone, and sacrifice fire and brilliance. While less expensive than diamonds shown as having Good and Very Good cuts, they do not have the sparkle people expect from a diamond. |
| Poor Cut: | Poorly cut diamonds that look dead to the eye. These diamonds are not recommended for fine jewelry. |
| Depth: | The height of a diamond (measured from the culet to the table). |
| Depth %: | The height of a diamond (measured from the culet to the table) divided by the width of the diamond. The depth % is critical to creating brilliance and fire in a diamond; a depth % that is too low or too high will cause a diamond to lack sparkle. |
| Eye-clean: | A diamond that has no inclusions visible to the naked eye. |
| Facet: | The flat polished surfaces on a diamond. A round brilliant diamond has 58 facets. |
| Fire: | Colored light reflected from within a diamond. Fire is maximized by cutting a diamond to the correct proportions. |
| Fluorescence: | A glow, usually of a bluish color, which emanates from certain diamonds when exposed to ultraviolet light. Strong fluorescence should be avoided, but faint fluorescence usually does not affect the appearance of a diamond. |
| Girdle: | The narrow band around the width of a diamond. The setting usually holds the diamond around the girdle. |
| Inclusion: | A flaw within a diamond, such as a spot or irregularity in the crystal structure of the stone. Inclusions can either be visible with the naked eye (usually SI2 clarity and below) or visible only under magnification. |
| Make: | The proportions to which a diamond has been cut. A good make will have proportions that maximize the brilliance and fire of a diamond. A poor make will lead to a diamond that has little sparkle due to the inability of the cut to properly reflect light. |
| Pavilion: | The bottom portion of a diamond, from just below the girdle to the bottom. |
| Point: | A weight measure equal to one one-hundredth of a carat. (A 0.50 carat diamond is said to be 50 points.) |
| Polish: | A grade given to the external finish of a stone. The polish scale ranges from poor to excellent. |
| Sparkle: | The combination of fire and brilliance; the amount of light that reflects out of a diamond. |
| Symmetry: | A grade given to the overall uniformity of a stones cut. The scale for symmetry ranges from poor to excellent. Poor symmetry will hurt the sparkle of a diamond. Diamonds with symmetry grades of good to excellent are recommended. |
| Table: | The largest facet on a diamond, located on the top of the diamond facing out from the setting. |
| Table %: | The width of the table divided by the total diameter of the diamond. The table % is critical to creating sparkle in a diamond; a table % that is too low or too high will cause a diamond to lack sparkle. |
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5770 NW Expressway, Suite 101
Oklahoma City, OK 73132
(405) 495-6610
FAX (405) 728-1914
Email: gems@customfinejewelry.com
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