Wollastonite: FL orange-yellow, SW
Calcite: Non-FL.
This is a beautiful wollastonite specimen from the Noble Pit at Sterling Hill, Ogdensburg, New Jersey. Noble Pit wollastonite specimens have different degrees of fluorescence, and while Noble Pit material isn't generally as bright as what came out of the lower mines, some of it is pretty close.
Wollastonite is a calcium silicate. It occurs at this locality with pyrite, diopside, calcite, and sometimes small amounts of galena and sphalerite.
If I recall correctly, manganese is the activator for fluorescent wollastonite. Perhaps the calcite in the specimen above doesn't fluoresce because the wollastonite "ate up" the available manganese when the rock formed. That's just a guess, but it makes sense. When there's manganese to go around in excess, I'd imagine one ends up with the two-color wollastonite-calcite specimens that came from the lower mines... where (guess what) there was more manganese.
Another idea that supports this is that much of the black, spinel-group mineral in the Noble Pit is not franklinite; it's magnetite. Aha! Are we on to something here? The answer is probably in Dr. Dunn's monograph, but I don't have it handy at the moment..
Photo is shown here with permission.
Wollastonite photo is copyright 2003, CR Scientific
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