Scheelite: Difference between revisions

Although it is now{{when}} uncommon as a diamond imitation (much more convincing products, like [[cubic zirconia]] and [[moissanite]] have long since superseded it), synthetic scheelite is occasionally{{when}} offered as natural scheelite, and collectors{{who}} may thus be fooled{{by who#} into paying high{{quantify}} prices for them. [[Gemology|Gemologists]] distinguish natural scheelite from synthetic material mainly by microscopic examination: Natural material is very seldom without internal growth features and inclusions (imperfections), while synthetic material is usually very clean. Distinctly artificial curved striae and clouds of minute gas bubbles may also be observed{{by who}} in synthetic scheelite.

The visible [[absorption spectrum]] of scheelite, as seen by a hand-held (direct-vision) [[spectroscope]], may also be of use: most natural stones show a number of faint absorption lines in the yellow region of the spectrum (~585 nm) due to [[praseodymium]] and [[neodymium]] trace impurities. Conversely, synthetic scheelite is often{{when}} without such a spectrum. Some synthetics may however be [[dopant|doped]] with neodymium or other [[rare-earth element]]s, but the spectrum produced is unlike that of natural stones.{{citation needed|date=December 2020}}