Term
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Definition
| lacking a regular crystal structure |
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Term
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Definition
| kinds and relative quantities of atoms that make up a material |
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Term
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Definition
| written description of a material's chemical make-up |
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Term
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Definition
| any gem material other than diamond |
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Term
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Definition
| regular, repeating internal arrangement of atoms in a material |
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Term
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Definition
| a gemstone's ability to withstand wear, heat, and chemicals |
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Term
| Federal Trade Commission (FTC) |
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Definition
| a US government agency that issues guidelines for the jewelry trade |
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Term
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Definition
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Term
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Definition
| a broad gem category based on chemical composition and crystal structure |
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Term
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Definition
| a subcategory of species, based on color, transparency, or phenomenon |
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Term
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Definition
| a family of gems from several closely related mineral species |
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Term
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Definition
| how well a gemstone resists scratches and abrasion |
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Term
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Definition
| composed of, or arising from, non-living matter |
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Term
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Definition
| the appearance of a material's surface in reflected light |
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Term
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Definition
| a natural, inorganic substance with a characteristic chemical composition and usually characteristic structure |
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Term
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Definition
| gems produced by natural processes, without human help |
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Term
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Definition
| one living, or produced by a living organism (plant or animal) |
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Term
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Definition
| an unusual optical effect displayed by a gem |
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Term
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Definition
| how well a gemstone resists the effects of light, heat and chemicals |
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Term
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Definition
| a laboratory creation with essentially the same chemical composition, crystal structure, and properties as its natural counterpart |
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Term
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Definition
| how well a gemstone resists breaking, cleaving, or fracturing |
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Term
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Definition
| atoms in a gem that aren't part of its essential chemical composition |
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Term
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Definition
| degree to which a material allows light to pass through it |
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