CompuServe Messages

Hi, Howard– At last, a new fluorescent mystery! The brightest longwave-UV yellow fluorescences I know of come from scapolite (meionite, generally) from Ontario/Quebec. Wollastonite and pectolite are also notable for this. Hydrocarbon inclusions in minerals often fluoresce a bright yellowish-white, as do hydrocarbon minerals such as idrialite (which also tends toward the green in visible-light coloring). Various phosphate minerals may also do this, at least apatite and pyromorphite. If there were a green component to the color, I would immediately suspect a uranyl-doped mineral, and the radiation clue would fit nicely. Phyllosilicates that might show yellow or white under longwave are: fluorapophyllite, tuscanite, pyrophyllite, talc, montmorillonite (I have only white listed, not remarkably bright), halloysite, and sepiolite. I have one casual indication of a modest white response from kaolinite. Calcite and aragonite flouresce bright yellow-white if the right amount of lead is present – any fizz? Given these limited facts, and my limited knowledge of what can and cannot be expected from the environmental clues you give, the above surely does not cover all the possibilities, and doubtless include a lot of red herrings. I could improve it somewhat with more details about the fluorescence, and what minerals are most expected from radioactive bentonites (in giving special attention to montmorillonite, I exhausted my knowledge of bentonite) or ash derivatives in general. Are we talking radioactive like granite, or radioactive like high-grade uranium ore here? An article in The Sciences (not Science) magazine of Jan/Feb 1995 discusses paleontological signal processing, particularly use of a technique called "convolution" to extract some notion of original deposition rates that had been obscured by mixing among layers as they formed. Perhaps this would allow establishing where the radiation originates if one cannot slice up the cores and/or there has been layer mixing. Can you describe the brightness and precise color in terms of any "commonplace" (to fluorescent colors) mineral specimens? If I knew you meant as bright as Ontario/Quebec wernerite (meionite/scapolite), I would zero in on the very brightest of the above, for example. Is it more on the green side or the orange side of yellow? Is it too white to match wernerite? Is there visible phosphorescence? You would need dark-adapted eyes to be sure of this. I am surprised you use only longwave UV; shortwave UV causes reactions among minerals considerably more often than longwave, and comparing the two can be informative. While shortwave was once too expensive, and remains more expensive than longwave, the last decade has seen longer-lasting filters appear, making its cost more manageable. If you want to send me a sample, I would be happy to comment on what I see with my lamps; I would be better able to compare it with my own specimens and knowledge. I am strictly an amateur in these matters, and thus would not know how to give it any special treatment to preserve its full scientific value. –Doug