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Details Title: Diamond Essentials - GIA Description: Diamond essentials study tools Total Flash Cards: 100 Created: 04/01/2007 20:22:18	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term Crown Angle Definition The angle formed by the bezel facets and the girdle plane Term Dispersion Definition The separation of the white ligth into spectral colors Term baguette Definition a small four sided setp cut thats rectangular, square or tapered Term Branded cut Definition cutting style thats developed, named and promoted by a specific manufactuer Term Brilliance Definition The birghtness created by the combination of all the whith light feflections from the surfact and the inside of a polished diamond Term Brilliant cut Definition cutting style with trainglar or kite shaped facets that radiate from the center toward the girdle Term Clarity Chacteristics Definition the collective term for inclusions and blemishes Term Crown Definition top part of the gem above the girdle Term Culet Definition Small facet at the bottom of a finished gem Term Durability Definition a gemstones ability to wothstand wear, heat and chemicals Term Facet Definition a flat, polished surface on a finished gem Term Fancy Cut Definition any gemstone shape other than round Term Fire Definition the flashes of color you see in a polished gem Term Four C's Definition four VALUE factors (color, clarity, cut and carat) that descripe the quality of a finished diamond Term Gem Quality Definition rough gem material that requires normal processing to produce a polished gem suitalbe for use in jewelry Term Girdle 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. Term Hardness Definition How well a gemstone resists SCRATCHES and ABRASION Term Inclusion Definition Clarity characteristic totally enclosed in a polished gemstone or extending into it from the surface Term Industrial quality Definition rough gem material suitable for the use in tools, drills, abrasives and other indusrial applications. Term Karat Definition A unit of measure for hte fineness of gold Term Metric carat Definition the international unit of measurement for gem weight. One carat equals 1/5th of a gram (.200g) Term Mixed cut Definition cut that combines brilliant-cut and step cut styles Term Mohs scale Definition ranking of the relative hardness of 10 minerals Term Near-Gem quality Definition rough gem materialthat requires substantially more processing thatn gem-quality rough t produce a polished gem suitable for use in jewelry Term Pavilion Definition lower part of a faceted gem below the girdle Term Point Definition One hundredth of a carat (.01ct) Term Scintillation Definition The flashes of light you see when the diamond, the light or the observer moves Term SImulant Definition A natural or manmade material that RESEMBLES a gem. Also called an imitation. Term Single cut Definition A round stone with 17 or 18 facets Term Standard round brilliant Definition a round brilliant cut stone with 57 or 58 facets. Often called a full cut. Term Step Cut Definition a cutting syle that features long, narrow facets in rows (usually 3) parallel to the girdle on both the crown and pavilion. Term Synthetic gem Definition a manmade gem with essentially the same chemical composition, crystal structure and properites asas a natural gem. Term Thermal shock Definition Damage caused by sudden extreme temperature changes Term Toughness Definition How well a gemstone resists breaking and chipping Term Value factors Definition features uses to judge the quality and value of all gemstones Term Microscopse are useful tools in a retail setting True or False? Definition True Term By hiding clarity characeristics, a cutter can improve the clarity of a diamond, True or False? Definition True Term Fracture filling imporves the apparent or actual clarity of a diamond? Definition Apparent Term Blemishes usually effect the top two clarity grades.. while inclusions effect ALL graded, True or False? Definition True Term Define: Bruting Definition Forming the basic face up outline of a diamond to prepare it for faceting Term Define: Feather Definition A collective term for diamond CLEAVEGES and FRACTURES Term Define: Fracture Filling Definition Treatment that involves injecting molten glass substance into a diamonds surface-reaching feathers or laser drill holes Term Define: Loupe Clean Definition Descripes a diamond that might have surface blemished, but shows no inclusions at 10x Term Define: Pique Definition A general term for included stones Term Define: Plot Definition A key colored diagram of a gemstones significant clarity charactersitics Term Define: A Natural Definition Part of the rough crystals origional surface left on a fashioned diamond Term A flawless diamond may have what characteristic? Definition Extra facets on the Pavilion not visable face up Term The 5 factors which determine the overall effect of a clarity characteristic are: Definition Size; Number; Position; Nature and Relief Term Define: Inclustion Definition Characteristics are enslosed within a gemstone. They may begin at the surface and move inward. Term Devine: Clarity range VVS Definition Diamonds which contain minute inclusions that are difficult for an experienced grader to see under 10x Term Define: Clarity range IF Definition When a diamond shows no inclusions under 10x by an experienced grader Term Define: Clarity range F Definition When a diamond shows no inclusions or blemishes under 10x by an experienced grader. Term Define: Inclustion "Bearded Girdle" Definition (BG) Tiny feathers extending in from the girdle, created during the bruting process Term Define: Inclusion "Bruise" Definition (Br) tiny opening or hole accompanied by tine, root-like feathers Term Define: Inclusion "Cavity" Definition (Cv) an opening or hole created when a crystal is pullled out, or when a feather breaks away Term Define: Inclustion "Cloud" Definition (Cld) a hazy or milky area make up of a number of very small inclusions grouped together Term Define: Inclusion "Feather" Definition (Ftr) a separation or break that reaches the surface, and is often white and feathery or shiny in appearance. Term Define: Inclusion "Grain Center" Definition (GrCnt) a small area of concentrated crystal structure distortion, usually with a pinpoint-like or thread like appearance Term Define: Inclustion "Included crystal" Definition (Xtl)a mineral crystal enclosed within a diamond Term Define: Inclusion "Indented natural" Definition (IndN) a natural that dips below the finished diamonds surface Term Define: Inclusion "Internal graining" 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. Term Define: Inclusion "Internal laser Drilling" Definition (no abv.) laser drilling within a diamond that doesent reach the surfact; not plotted Term Define: Inclustion "Laser drill hole" Definition (LDH) a tiny tube made by a laser; the surface opening might resemble a pit, while the tube might resemble a needle Term Define: Inclusion "Needle" Definition (Ndl)a long, thin included crystal that looks like a tiny rod Term Define: Inclusion "Pinpoint" Definition (Pp) a very small included crystal, normally seen under 10x as a diny dot, either singly or in groups or strings Term Define: Blemish "Abrasion" Definition (Abr) a series of tiny nicks along facet junctions, producting white fuzzy lines instead of sharp facet edges Term Define: Blemish "Extra Facet" Definition (EF) a facet placed without regard for symmerty and not required by the cutting style. Term Define: Blemish "Lizard Skin" Definition (no abv) wavy or bumpy area on teh surface ofa polished diamond Term Define: Blemish "Natural" Definition (N) part of the orgional surface of rough diamonds surface that remains on the polished stone Term Define: Belmish "Polish Lines" Definition (PL) fine parallel groves an ridges left on a gems facet as a result of the polishing process Term Define: Blemish "Polish Mark" Definition (PM) whitish film on the surface of a facet caused by excessive heat during polishing. Term Define: Blemish "Rough girdle" Definition (RG) a grainy or pitted girdle surface, often with nicks Term Define: Blemish "Scratch" Definition (S) a linear indentation normally seen as a fine white line, curved or straight, with no apparent depth. Term Define: Blemish "Surface Graining" Definition (SGr) Surface indication of structural irregularity; might appear as a groved or wavy surface; might cross facet junctions Term Define: Annealing Definition A gemstone heating process that can be used alonr or to stabilize irradiated color Term Define: Color Characteristic Definition The basic color of a fancy colored gemstone Term Define: Depth of Color Definition The combination ot TONE and SATURATION that determines how noticiable the color is. Term Define: Fancy colored diamonds Definition Naturally colored yellow and brown diamonds that exhibit color beyone the Z range, or that exhibit any othe color face up. Term Define: Fluoresence Definition The emission of visible light by a material when its exposed to ultraviolet radiation Term Define: Hue Definition Your first impression of a color; the basic color of an object Term Define: Irradiaion Definition A treatment that changes the clolor of a gem by exposing it to radioactive materials Term Define: Masterstones Definition A set of color comparision diamonds that defines GIA's diamond color grades in the normal (D-Z) range Term Define: Near-Colorless Definition A general term for diamonds in teh G-to-J color range Term Define: Normal Color Range Definition Tande of diamonds colrs from colorless to light yellow and light brown Term Define: Saturation Definition A colors strength or intensity, ranging from a dull hue to a pure, vivid hue Term Define: Tone Definition A colors degree of darkness or lightness Term Degine: Ultraviolet Definition (UV) light wavelength that's invisiable to the human eye Term Each letter grade in the GIA color scal represents? Definition A range in color Term The top grade of the NORMAL GIA color range is? Definition D Term The most common color of fluorescencs in gem quality diamond is? Definition Blue Term Which of the following grades has the most yellow? D, G, I, H Definition I Term The most commonly encountered colors amoung fancy colored diamonds are? Definition Brown and Yellow Term Which masterstone does GIA Gem Trade Lab use to determine if a natural yellow diamonds qualifies as a fancy yellow? Definition Color grade Z Term The color grade a light yellow or brown diamond, graders compair it to a masterstone for? Definition Hue, Tone and Saturation Term The annealing of irradiated diamonds to stabilize their color is done by? Definition Heating Term The combination of tone and saturation that determines how noticable a color is, is know as? Definition Hue Term When mounted, G,H and I diamonds can look? Definition Colorless face up Term If all factors are equal, the more rare diamonds are? Definition Pink and Blue Term Irradiated diamonds might change color when expesed to? Definition Heat Term Most consumers can easliy see color beyond the color grade? Definition M