Sunday, November 20, 2011
Helpful Jewelry Information About Diamonds
9:50 AM | 
Posted by
bayan |
| Baguettes | Small rectangular cut diamond used primarily for trim or accent. |
| Blemish | A term used to describe an imperfection on the surface of a finished diamond, such as a scratch or cavity. |
| Blue Diamond | A diamond with a distinct blue body color, usually a light blue. |
| Blue White | A term used to describe a colorless diamond. The FTC ruled that the stone must have a bluish tint. Flagrant misuse has made the term meaningless. |
| Body Color | The color of a diamond as seen in diffused light against a neutral background, free from surrounding reflections. |
| Brilliance | The intensity of the white light reflected from the surface and the internal surfaces of the facets on a diamond in the "Face Up" position. |
| Brilliant Cut | Diamonds fashioned in the round shape with 58 facets. It is the most efficient cut for diamonds cut from octahedral rough. |
| Canary Diamond | Trade name for a yellow diamond with very intense yellow/green or yellow/orange color. |
| Cape | Trade name for diamonds showing distinct yellow tint as seen "Face Up". |
| Carat Weight | Unit of weight for diamonds and other precious stones. A Metric Carat = .200grams = 100 points. |
| Carbon Spots | Black appearing spots in diamonds when seen at certain angles. Wrong term for dark inclusions. |
| Cavity | A hole or indentation on the surface of a diamond. |
| Certificate | A written report stating all quality factors of a diamond. Price is not stated. |
| Champagne Diamond | A trade term describing a light yellow diamond with green or brown overtone but lacks the intensity to be a Fancy Color Diamond. |
| Chip | #1. A small irregular piece of diamond. #2. A small break on the surface of a diamond usually extending into the crown or pavilion if located on the girdle. It can also extend in any direction from a facet edge. |
| Clean | Frequently misused term to describe a diamond with slight imperfections. Can also be used to describe a diamond with internal imperfections. Use is prohibited by the FTC unless the stone qualifies as "perfect" as described by the Commission. |
| Cleavage | Usually describes an internal crack or break in a diamond along a cleavage plane. |
| Colorless | A diamond with absolutely NO body color. Stone must be completely transparent. |
| Commercially Perfect | A term used to describe the clarity of a diamond and implies that the stone is nearly perfect. (See FTC's definition) |
| Commercial White | A misleading term used to imply that a stone is nearly white, but is actually off color. see Colorless |
| Crack | A cleavage fracture or fissure with an irregular path inside the stone, usually breaks the surface of the stone. |
| Crown | The portion of the diamond above the girdle. |
| Cubic Zirconia | A man-made simulated diamond that is frequently mistaken for a diamond. It does not occur in gem as quality natural stone. |
| Culet | Small facet polished at the buttom of the diamond, parallel to the table. Usually seen on Old Mine or Old European Cut diamonds. Helped to prevent damage to the older cut stones. If it is too large, it appears as a "hole" in the stone. |
| Dispersion | The breaking up of white light into all the colors of the rainbow. |
| Emerald Cut | Refers to a rectangular shaped diamond with long parallel facets on the crown and the pavilion. The overall shape is eight sided. |
| Eye Clean | A term used to describe a diamond that has no flaws visible to the unaided eye of a diamond expert, usually misused. see FTC description of "FLAWLESS" |
| Facet | A flat angular surface polished on the surface of a diamond. |
| Face Up | A gemstone as seen with the viewer looking directly at the top of the stone. |
| Feather | An internal cleavage with the appearance of a feather. |
| Filled Diamond | A diamond that had a transparent filler forced into cracks, cleavages or crevices under heat and pressure in order to improve the appearance of the stone. |
| Fire | Flashes of the rainbow colors from a diamond caused by dispersion. |
| Fish Eye | An exceedingly shallow diamond with a noticeable lack of brilliancy. The girdle is usually reflected under the table edge. |
| Flaw | A term used to describe any external or internal imperfection in a diamond. |
| Flawless | A term used to describe a diamond that is totally void in external or internal flaws or blemishes of any kind, as seen by a trained eye with a 10X magnifier, under ideal lighting conditions. FTC rules permit the use of the word "FLAWLESS" without any reference to color or cut. |
| Fluorescence | Blue, yellow or white glow as seen on a diamond when viewed in ultra-violet light or strong sunlight. |
| Fracture | see "Crack" |
| Full Cut | A term used to describe diamonds with 58 facets. |
| Gem Color | A term usually used to imply that a diamond is colorless, when in fact, the stone is average to good color. |
| Gemologist | A person who has completed studies in DIAMONDS, COLORED STONES and GEM IDENTIFICATION. He or she should have sufficient experience in the jewelry business to properly apply these studies to appraisals. |
| Girdle | The edge of a diamond or other precious stone. |
| Head | The portion of the mounting that actually holds the diamond. |
| Heart Shape | A diamond that is fashioned in the shape of a heart. |
| Inclusion | A visible foreign substance or crystal inside a diamond. see "Flaw" |
| Included Crystal | An enclosed crystal of mineral or another diamond inside a diamond. |
| Industrial Diamond | A diamond used in drilling or cutting tools. Usually very heavily flawed and thus not suitable for the gem trade. |
| Internally Flawless | A term that describes diamonds that are completely free of all inclusions but may have very minor surface blemishes, which could be removed by repolishing. |
| Laser Drilled | Drilling diamonds with laser beams in order to enhance the appearance of a diamond by providing a means to allow a bleaching substance to turn a dark flaw to white. |
| Loupe | A small magnifying glass, either hand held or placed in the eye socket. A 10X loupe should be used to examine diamonds. |
| Loupe Clean | Usually a misused term to describe a diamond as being free of flaws with magnification. SEE "PERFECT" OR "FLAWLESS" |
| Make | Refers to the proportions and finish of a polished diamond. |
| Marquise Cut | A boat shaped diamond that is pointed at both ends. |
| Master Diamonds | Diamonds certified for body color. They are used to determine the color of other diamonds by comparing the unknown with the known color of the Master Diamond. |
| Moissanite | A man made diamond substitute frequently mistaken for diamond. It does not occur as a natural stone. |
| Mounting / Setting | A term that describes an article of jewelry that holds gemstones. |
| Natural | A portion of the original surface of a rough diamond left on a cut and polished diamond, usually found on the girdle. It can extend into the crown or pavilion. |
| Nick | Small chip or indentation on the surface of a diamond. Usually found on the girdle. |
| Octahedron | Most common form of rough diamonds. Try to picture a small pyramid one on top of another, base to base for a general idea of this crystal structure. It is the best shape of rough for cutting brilliant cut diamonds. |
| Old European Cut | A diamond with a round girdle outline. It will usually have a high crown, a small table, a deep pavilion and a large culet. |
| Old Mine Cut | A diamond with a squarish girdle outline. It will usually have a high crown, a small table, a deep pavilion and a large culet.. |
| Oval Cut | Elliptical shaped diamond, both ends are rounded. It is a variation of the brilliant cut. |
| Pavilion | The portion of the diamond below the girdle. |
| Pear Shape | A variation of the brilliant cut with one pointed end and one rounded end. |
| Perfect | FTC rules state that a diamond must be free from any and all imperfections when examined by a trained expert with a 10X magnifier in ideal lighting conditions. In addition, the stone must be absolutely colorless and conform to ideal proportions. Such stones are extremely rare. |
| Perfect Cut | A term used to describe a stone that has been cut to ideal proportions. Such stones are relatively rare. The term is often confused with Perfect. |
| Pin Point | A small rounded inclusion but not discernable as an included crystal at 10X magnification. |
| Polish | #1. The smoothness of a facet surface. #2. The act of applying facets to a diamond. |
| Polished Girdle | Usually a girdle edge that has been finished to a high polish or a series of small facets all around the edge of the stone. Most girdles have a gray waxy appearance. |
| Princess Cut | A nearly square or rectangular stone with brilliant faceting above and below the girdle. |
| Proportions | Describes the cutting quality relative to the Table Percentage, Depth Percentage, Girdle Percentage, Crown and Pavilion angles and symmetry. |
| Radiant Cut | Similar to the Princess Cut with additional brilliant faceting on the four corners, thus giving the stone an eight-sided outline. |
| Reflection | The rebounding of light rays from the facet surfaces on a diamond. |
| Refraction | The bending of light rays when they enter or leave a diamond. |
| Scintillation | That twinkling of reflected light when a diamond is moved, or the viewer moves or the light source moves. |
| Shank | Portion of a ring that encircles a finger. It holds the head, which in turn, holds the diamond. |
| Simulated Diamond | Any material made and cut to look like a diamond. These stones may be natural or man-made but will not have any of the properties of a diamond. |
| Single Cut | A small round diamond, usually under 0.05 ct. with 17 facets. |
| Solitaire | A ring set with a single diamond. |
| Spread | Describes a diamond that has been cut with a thin crown and a large table in order to retain extra weight. see Fish Eye |
| Symmetry | The exactness in shaping a diamond and the placing of the facets on the stone. |
| Synthetic Diamond | A man-made diamond with all the physical and chemical properties of the natural diamond. |
| Table | The large octangular facet on top of the crown on a round diamond. |
| Tapered Baguette | A modified baguette, narrower at one end. Usually used for trim and accent. |
| Tiffany Mounting | Usually refers to a solitaire mounting with a four or six prong head to hold the diamond. The shank is usually quite simple and narrow. |
| Treated Diamond | Any diamond that has been lasered, filled, coated or bombarded in a reactor to change the color or improve the appearance of the stone. |
| Trillion | A triangular shaped stone with slightly curved girdle edges cut with brilliant faceting. |
| Yag | A man-made material used in lasers that duplicates the atomic structure of garnet. Its technical name is YTTRIUM ALUMINUM GARNET. Colorless YAG is used as a simulant for diamond. It was replaced with Cubic Zirconia. |
| Zirconia | A man-made simulated diamond that is frequently mistaken for diamond. It does not occur as a natural stone in gem quality. |
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Gold Basics
