At 01:31 PM 8/17/99 -1200, you wrote:
>Carole, Paul et al
>
>Thanks for the advice. Fossil shells don't generally fluoresce strongly, in
>fact most are pretty weak, but nevertheless many do glow.

Andrew:

Obviously you have not seen Pliocene (some lower Pleistocene) mollusca from
south Florida, if you think that fossil shells cannot fluoresce strongly.
Even without dipping in the bleach (mentioned last time), the patterns can
be spectacular - especially Cones, Volutes, Mitras and Naticas.  Heck, even
the Olives show some patterns.  Apparently, the bleach treatment can really
bring out the colors.  I do not have much of a recent collection, other
than Olividae, but the recent cones that I have (about 30 species) do not
show as much fluorescence as the fossil ones!  Now, the one Cypraea mappa
from Papua New Guinea that I have is a different story - WOW - the red
fluorescence of that recent shell in incredible!!!

In all my years of planning, I have never gotten the chance to get to south
Florida to collect (i.e., pregnancies [wife's], children, weather
[including one hurricane that got in the way], health problems, you name
it).  The late Shirley Hoerle, who some of you might remember, one day gave
me a box of Pinecrest Formation (Lower Pliocene? - changes all the time)
fossils that came from Tulane University locality 729 described as "Spoil
Banks on west side of Kissimmee Canal and East side of Kissimmee River,
approximately 1/2 mile south of U.S. Corps of Engineers Structure 63-D
(Section 33, T36S, R33E), Okeechobee County, Florida."  I only have a small
box, but I just took them out and put them under my 30 year old UV light
(short wave is better) and they light up!!  I only have a few of these, but
perhaps someone in south Florida could send you a few of these so you can
have a real appreciation of how some fossil shells can fluoresce under UV
light!

I could also give you the address of a couple of people who have done this
in the past and published plates of flourescent patterns in journal
articles.  If you cannot get access to the journal "Tulane Studies in
Geology and Paleontology", let me know and I will xerox some articles and
send them to you.

Paul

>
>One problem I can think of with UV is that glass fluoresces and loses some
>transparency. If the camera lens itself is hit by any stray UV it will
>fluoresce diml violet, which may be enough to reduce crispness of the
>image. it would be important to ensure the lens is shaded from direct UV.
>
If you can get access to "Tulane Studies in Geology and Paleontology" at
the local university, I will send the referenced articles that I referred
to last time.  You will see that the plates (sorry, only black & white) are
superb and the patterns are very sharp under the UV light.

Paul

>I did get our Dept photographer to try B&W photography. He got some results
>with about 3-minute exposures, but lost interest. I don't know what film he
>used, but suspect his favorite, Ilford FP4. i guess if 400ASA film needs 1
>minute exposure for a brightly-fluorescing Recent shell, the same film
>would need at least 2-3 minutes for a dim fossil. I'll give it a go with
>color film.
>
Can't help - no actual hands-on experience, just what I have seen as the
final product of others.

>Regards
>Andrew
>
>