[Rockhounds] Re: Halite losing fluorescence

[Scott Blair]

I'm undereducated on this but interested none-the-less, because I collect at Searles Lake during the annual field trip. The daylight pink color, as I understand it, is due to the presence of halobacteria, which have a red pigment in them. If this pigment is an activator for fluorescence, I assume it could break down, being organic. I read an interesting transcript on red fluorescence in halite being due to the presence of manganese and lead as co-activators in some deposits. Apparently the manganese can oxidize, leading to loss of fluorescence: www.minsocam.org/ammin/AM31/AM31_527.pdf The pink halite cubes are often attached to a matrix of burkeite, which can be gray. But I've never seen the pink cubes themselves turn gray. The halobacteria seem to thrive in certain zones in the brine ponds which dot the surface of the lake. Even in the same brine pond, the halite will be unequally colored - some could be deep burgandy, while some will be only lightly blushed with pink, and some can be white. The collecting area on the lake is large, and differing conditions exist among the brine ponds, and year to year, depending on natural conditions such as rainfall, and also on lake flow management - it's operated as a chemical plant the other 364 days of the year, when we "tourists" aren't out there. So it's conceivable that one piece of halite could be a little different chemically than another, even though the locality is the same.  Regards - Scott Blair

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---