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Definition
| The angle formed by the bezel facets and the girdle plane |
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Definition
| The separation of the white ligth into spectral colors |
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Definition
| a small four sided setp cut thats rectangular, square or tapered |
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Definition
| cutting style thats developed, named and promoted by a specific manufactuer |
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Definition
| The birghtness created by the combination of all the whith light feflections from the surfact and the inside of a polished diamond |
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Definition
| cutting style with trainglar or kite shaped facets that radiate from the center toward the girdle |
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Definition
| the collective term for inclusions and blemishes |
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Definition
| top part of the gem above the girdle |
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Definition
| Small facet at the bottom of a finished gem |
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Definition
| a gemstones ability to wothstand wear, heat and chemicals |
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Definition
| a flat, polished surface on a finished gem |
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Definition
| any gemstone shape other than round |
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Definition
| the flashes of color you see in a polished gem |
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Definition
| four VALUE factors (color, clarity, cut and carat) that descripe the quality of a finished diamond |
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Definition
| rough gem material that requires normal processing to produce a polished gem suitalbe for use in jewelry |
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Definition
| The narrow section of a finished gem that forms the boundary between the crown and the pavilion and functions as the gems setting edge. |
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Definition
| How well a gemstone resists SCRATCHES and ABRASION |
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Definition
| Clarity characteristic totally enclosed in a polished gemstone or extending into it from the surface |
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Definition
| rough gem material suitable for the use in tools, drills, abrasives and other indusrial applications. |
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Definition
| A unit of measure for hte fineness of gold |
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Definition
| the international unit of measurement for gem weight. One carat equals 1/5th of a gram (.200g) |
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Definition
| cut that combines brilliant-cut and step cut styles |
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Term
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Definition
| ranking of the relative hardness of 10 minerals |
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Term
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Definition
| rough gem materialthat requires substantially more processing thatn gem-quality rough t produce a polished gem suitable for use in jewelry |
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Definition
| lower part of a faceted gem below the girdle |
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Term
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Definition
| One hundredth of a carat (.01ct) |
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Definition
| The flashes of light you see when the diamond, the light or the observer moves |
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Term
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Definition
| A natural or manmade material that RESEMBLES a gem. Also called an imitation. |
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Term
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Definition
| A round stone with 17 or 18 facets |
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Term
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Definition
| a round brilliant cut stone with 57 or 58 facets. Often called a full cut. |
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Definition
| a cutting syle that features long, narrow facets in rows (usually 3) parallel to the girdle on both the crown and pavilion. |
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Definition
| a manmade gem with essentially the same chemical composition, crystal structure and properites asas a natural gem. |
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Definition
| Damage caused by sudden extreme temperature changes |
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Definition
| How well a gemstone resists breaking and chipping |
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Term
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Definition
| features uses to judge the quality and value of all gemstones |
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Term
| Microscopse are useful tools in a retail setting True or False? |
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Definition
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Term
| By hiding clarity characeristics, a cutter can improve the clarity of a diamond, True or False? |
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Definition
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Term
| Fracture filling imporves the apparent or actual clarity of a diamond? |
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Definition
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Term
| Blemishes usually effect the top two clarity grades.. while inclusions effect ALL graded, True or False? |
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Definition
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Term
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Definition
| Forming the basic face up outline of a diamond to prepare it for faceting |
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Term
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Definition
| A collective term for diamond CLEAVEGES and FRACTURES |
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Term
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Definition
| Treatment that involves injecting molten glass substance into a diamonds surface-reaching feathers or laser drill holes |
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Term
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Definition
| Descripes a diamond that might have surface blemished, but shows no inclusions at 10x |
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Term
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Definition
| A general term for included stones |
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Term
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Definition
| A key colored diagram of a gemstones significant clarity charactersitics |
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Term
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Definition
| Part of the rough crystals origional surface left on a fashioned diamond |
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Term
| A flawless diamond may have what characteristic? |
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Definition
| Extra facets on the Pavilion not visable face up |
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Term
| The 5 factors which determine the overall effect of a clarity characteristic are: |
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Definition
| Size; Number; Position; Nature and Relief |
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Term
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Definition
| Characteristics are enslosed within a gemstone. They may begin at the surface and move inward. |
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Term
| Devine: Clarity range VVS |
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Definition
| Diamonds which contain minute inclusions that are difficult for an experienced grader to see under 10x |
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Term
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Definition
| When a diamond shows no inclusions under 10x by an experienced grader |
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Term
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Definition
| When a diamond shows no inclusions or blemishes under 10x by an experienced grader. |
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Term
| Define: Inclustion "Bearded Girdle" |
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Definition
| (BG) Tiny feathers extending in from the girdle, created during the bruting process |
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Term
| Define: Inclusion "Bruise" |
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Definition
| (Br) tiny opening or hole accompanied by tine, root-like feathers |
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Term
| Define: Inclusion "Cavity" |
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Definition
| (Cv) an opening or hole created when a crystal is pullled out, or when a feather breaks away |
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Term
| Define: Inclustion "Cloud" |
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Definition
| (Cld) a hazy or milky area make up of a number of very small inclusions grouped together |
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Term
| Define: Inclusion "Feather" |
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Definition
| (Ftr) a separation or break that reaches the surface, and is often white and feathery or shiny in appearance. |
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Term
| Define: Inclusion "Grain Center" |
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Definition
| (GrCnt) a small area of concentrated crystal structure distortion, usually with a pinpoint-like or thread like appearance |
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Term
| Define: Inclustion "Included crystal" |
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Definition
| (Xtl)a mineral crystal enclosed within a diamond |
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Term
| Define: Inclusion "Indented natural" |
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Definition
| (IndN) a natural that dips below the finished diamonds surface |
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Term
| Define: Inclusion "Internal graining" |
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Definition
| (IntGr) internal indications of irregular crystal growth; may appear like faint lines or streaks agains a transparent background, or may appear milky, colored or reflective. |
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Term
| Define: Inclusion "Internal laser Drilling" |
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Definition
| (no abv.) laser drilling within a diamond that doesent reach the surfact; not plotted |
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Term
| Define: Inclustion "Laser drill hole" |
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Definition
| (LDH) a tiny tube made by a laser; the surface opening might resemble a pit, while the tube might resemble a needle |
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Term
| Define: Inclusion "Needle" |
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Definition
| (Ndl)a long, thin included crystal that looks like a tiny rod |
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Term
| Define: Inclusion "Pinpoint" |
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Definition
| (Pp) a very small included crystal, normally seen under 10x as a diny dot, either singly or in groups or strings |
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Term
| Define: Blemish "Abrasion" |
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Definition
| (Abr) a series of tiny nicks along facet junctions, producting white fuzzy lines instead of sharp facet edges |
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Term
| Define: Blemish "Extra Facet" |
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Definition
| (EF) a facet placed without regard for symmerty and not required by the cutting style. |
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Term
| Define: Blemish "Lizard Skin" |
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Definition
| (no abv) wavy or bumpy area on teh surface ofa polished diamond |
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Term
| Define: Blemish "Natural" |
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Definition
| (N) part of the orgional surface of rough diamonds surface that remains on the polished stone |
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Term
| Define: Belmish "Polish Lines" |
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Definition
| (PL) fine parallel groves an ridges left on a gems facet as a result of the polishing process |
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Term
| Define: Blemish "Polish Mark" |
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Definition
| (PM) whitish film on the surface of a facet caused by excessive heat during polishing. |
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Term
| Define: Blemish "Rough girdle" |
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Definition
| (RG) a grainy or pitted girdle surface, often with nicks |
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Term
| Define: Blemish "Scratch" |
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Definition
| (S) a linear indentation normally seen as a fine white line, curved or straight, with no apparent depth. |
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Term
| Define: Blemish "Surface Graining" |
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Definition
| (SGr) Surface indication of structural irregularity; might appear as a groved or wavy surface; might cross facet junctions |
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Term
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Definition
| A gemstone heating process that can be used alonr or to stabilize irradiated color |
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Term
| Define: Color Characteristic |
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Definition
| The basic color of a fancy colored gemstone |
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Term
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Definition
| The combination ot TONE and SATURATION that determines how noticiable the color is. |
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Term
| Define: Fancy colored diamonds |
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Definition
| Naturally colored yellow and brown diamonds that exhibit color beyone the Z range, or that exhibit any othe color face up. |
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Term
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Definition
| The emission of visible light by a material when its exposed to ultraviolet radiation |
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Term
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Definition
| Your first impression of a color; the basic color of an object |
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Term
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Definition
| A treatment that changes the clolor of a gem by exposing it to radioactive materials |
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Term
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Definition
| A set of color comparision diamonds that defines GIA's diamond color grades in the normal (D-Z) range |
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Term
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Definition
| A general term for diamonds in teh G-to-J color range |
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Term
| Define: Normal Color Range |
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Definition
| Tande of diamonds colrs from colorless to light yellow and light brown |
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Term
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Definition
| A colors strength or intensity, ranging from a dull hue to a pure, vivid hue |
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Term
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Definition
| A colors degree of darkness or lightness |
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Term
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Definition
| (UV) light wavelength that's invisiable to the human eye |
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Term
| Each letter grade in the GIA color scal represents? |
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Definition
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Term
| The top grade of the NORMAL GIA color range is? |
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Definition
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Term
| The most common color of fluorescencs in gem quality diamond is? |
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Definition
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Term
| Which of the following grades has the most yellow? D, G, I, H |
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Definition
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Term
| The most commonly encountered colors amoung fancy colored diamonds are? |
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Definition
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Term
| Which masterstone does GIA Gem Trade Lab use to determine if a natural yellow diamonds qualifies as a fancy yellow? |
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Definition
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Term
| The color grade a light yellow or brown diamond, graders compair it to a masterstone for? |
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Definition
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Term
| The annealing of irradiated diamonds to stabilize their color is done by? |
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Definition
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Term
| The combination of tone and saturation that determines how noticable a color is, is know as? |
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Definition
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Term
| When mounted, G,H and I diamonds can look? |
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Definition
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Term
| If all factors are equal, the more rare diamonds are? |
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Definition
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Term
| Irradiated diamonds might change color when expesed to? |
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Definition
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Term
| Most consumers can easliy see color beyond the color grade? |
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Definition
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