Term
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Definition
| the process of artifically altering the appearance and properties of a gem material |
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Term
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Definition
| artifical alteratio of the appearance and properties of gem material in order to improve its appearance, stability or saleability |
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Term
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Definition
| the practice of fixing shiny metal foil onto the back of the stone or between the stone and a closed-back setting |
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Term
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Definition
| the use of chemicals or other agents to lighten or remove the color of a gemstone |
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Term
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Definition
| the application of a colored layer to improve or change the color of the gem |
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Term
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Definition
| the alteration of the color or optical appearnce of a stone via color-causing elements from an outside source |
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Term
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Definition
| bombardment by atomic particles, or the emanations of radioactive substances; it may change the color of gemstones or produce enhanced color in pale gemstones |
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Term
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Definition
| fine holes drilled in diamonds by a laser beam follow by bleaching in order to make inclusions less noticeable |
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Term
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Definition
| uses the laser to heat a dark inclusion causing stress fractures that extend to the surface of the stone; the fractures can then be treated with acid to remove the dark inclusion |
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Term
| High Pressure High Temperature (HPHT) |
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Definition
| diamonds are exposed to high pressures of up to 60 kilobars and high temperatures of about 2000°C for a short period of time |
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