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About Minerals

Colors in Flourescent Minerals

Some of the elements that produce identifiable colors in minerals can be influenced by several factors. In decreasing importance these are:

  1. The valence state (chemical reaction state - amount of (+) charges) of the fluorescent element. An example of this is the use of phosphorus in laundry compounds where the charge (PO4) is in the 'plus-five state'. Chromium is usually +3. Valence state of a fluorescent mineral has a great deal to do with the color that the mineral will display under UV light-long or short wave.
  2. The presence of other trace or constituent elements that interact with, or interfere with the energy levels of the fluorescent-element valence electrons. These are called "co-factors" or "activators".
  3. Crystal structure and imperfections (dislocations) at the boundaries of the grain structure of a mineral that interact with UV light.

Note: Under regular light, the 'fire' of opals is due entirely to this phenomenon. (In #3)

Phosphorus (P) nearly always-bright bluish white under SW and LW

Uranium (U) always bright lime-green under SW and dull-green under LW

Via The Tumbler by Gerry Naugle 7/05, Quarry Quips, 4/01, from Flatiron Facets, 4/01