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 Citrine, which is rare, is yellow to orange-yellow, and occurs in much lighter hues than the heat-treated material, which is dark orange-brown to reddish-brown. Virtually all heat-treated material has a reddish tint, whereas the natural specimens do not.itrine is the yellow to brownish-red variety of the mineral Quartz. It is a widely used as a gemstone, and after Amethyst it is the most popular Quartz gem. Most Citrine is formed by heat treating purple Amethyst. Citrine may also be produced by heat-treating Smoky Quartz from certain localities.