In a computer language, a reserved word is a word that cannot be used as an identifier, such as the name of a variable, function, or label â it is reserved from use. This is a syntactic definition, and a reserved word may have no meaning. A closely related and often conflated notion is a keyword, which is a word with special meaning in a particular context. This is a semantic definition. By contrast, names in a standard library but not built into the language are not considered reserved ...
Document status: complete. Citrine is a transparent, yellow macrocrystalline quartz variety. Natural citrine is very rare, in fact almost all the material offered on the market under that name is not natural citrine, but heat treated amethyst.
Natural citrines are rare. Most commercial citrine is heat-treated amethyst or smoky quartz. Because the color is now caused by finely distributed iron minerals (mostly hematite and goethite), heated amethyst is not a citrine in the strict sense.Quartz colored by inclusions of any kind is not called a citrine.atural citrines are rare. Most commercial citrine is heat-treated amethyst or smoky quartz. Because the color is now caused by finely distributed iron minerals (mostly hematite and goethite), heated amethyst is not a citrine in the strict sense. Quartz colored by inclusions of any kind is not called a citrine.