FrOg On-Line #2001-04

Welcome to FrOg On-Line #2001-04, Monday, May 14, 2001


1. Introduction
2. Follow-Up to The Home Lab
3. "Subscriber" List

1. Introduction

Greetings.  Hopefully, y'all are recovered from the NJESA Show.

Sunday, April 29, in the saddle area between the Passiac and Noble Pits, one
of the collectors digging there asked to subscribe to FrOg On-Line, and gave me
a piece of paper with his e-mail address.  Unfortunately, I lost it, and I've
completely forgotten both his name and his e-mail address.  The only things I
do recall is that he is a Caucasian male, and he works for SAIC (Science
Applications International Corp.).  If anyone knows his name or a-mail address,
please let me know, or have him e-mail me.

The FrOg On-Line Archive has a new web address:
Chris Thorsten continues to host the archive.  His home page is now at
I have tried it; it works great.

This issue consists mainly of a discussion of Chris Thorsten's home lab work on
Monazite, first reported in FrOg On-Line #2001-03.

The next issue, already in preparation, will be dedicated to a discussion of
Charlesite and two of the FrOg mineral lists.

As far as I know, there are no new activities or events to be added to what was
in FrOg On-Line #2001-03, so see that issue for the schedule of events.


2. Follow-Up to The Home Lab

From: "earl verbeek" <>
Subject: monazite
Date: Mon, 09 Apr 2001 10:43:51 -0400

Good morning Chris,

Just read the latest FrOg issue and mention of monazite fluorescing under
unfiltered UV.  Minor correction there, as what you see is not fluorescence but
simple reflection, in this case of the very strong Hg emission line at .  .  .
what?  .  .  .  536 nm or so?  I can't remember the exact wavelength, but it's
in the green portion of the spectrum and is a whopper of a peak.  It's filtered
out by the SW filter, so monazite generally will not fluoresce green with a
filtered SW lamp (unless it's uranyl-activated, like the Madagascan material
seems to be), but the reflection of the Hg emission line under unfiltered SW is
a good test.

By the way, a number of other rare-earth minerals do this too, and it's
fortunate they do, because some of them can be quite inconspicuous in their
host rock.  The Mountain Pass, CA ores are a case in point, as some of them are
just loaded with rare-earth minerals but look like ordinary rocks until you
hold them under that unfiltered lamp.


From: "earl verbeek" <>
Subject: Re: monazite
Date: Mon, 09 Apr 2001 14:34:48 -0400

Hi Bill and Chris,

I have no objection to using my little note in a FrOg newsletter, IF it's OK 
with Chris.  I know some people are sensitive about corrections appearing in 
print, and I am one of them unless the correction is done tactfully and with an
intent to help.  I am not the one to judge whether that impression comes 
through in my note, so it's Chris' call.

Most monazite is tan to brown in daylight, and quite a few other rare-earth 
minerals are various pale colors, so they tend not to stand out very well in 
the rocks that contain them.  As far as I know the rare earths are not 
chromophores, thus explaining the general lack of vivid coloration.  And Bill,
you guessed just right, these minerals do selectively reflect light with a
wavelength near that of the mercury resonance line.  It's almost like holding
up a mirror.  When looking at unfiltered SW light we're not particularly aware
of how much green light is in it, but the selective reflection from the rare
earth minerals shows it quite nicely.

If I remember I'll try to look up an absorption spectrum for monazite and send
it to you.  I don't know if I have one on file, but I know where to look on the
Internet.  Bless you, CalTech.

                                         Cheers-   Earl


Date: Tue, 10 Apr 2001 00:55:57 -0400
From: Chris <>
To:, Bill Mattison <>
Subject: Re: monazite

Earl and Bill,

it's cool w/ me... I think it may be helpful to others to print it also.  I
don't think mercury-line reflection is a well-known or obvious enough fact that
someone's going to pounce on me and say "duh", so I'm okay with that... but I
appreciate Earl's consideration nonetheless.

By the way, the Buckwheat monazites and synchysites that I've seen in the
collections of the FMM, Steve Kuitems, and Joe Klitsch are typically pale
yellow, honey-lemon yellow (like a Luden's cough drop) or even pinkish-yellow -
and usually transparent.  Steve and Joe both have found quite a few of these
tiny crystals on the dump.  John C. has a couple of exceptional ones he's shown
me, too.  Unfortunately, there are none that would qualify as "cabinet
specimens"... sorry, Bill, no macro monazites yet   : )

-Chris Thorsten


Date: Tue, 10 Apr 2001 12:27:34 +0000
From: William Mattison <>
To: Chris Thorsten <>, Earl Verbeek <>
Subject: Hg Emission spectra.

Interesting discussion so far.  I'd like to see this phenomenon for myself one
of these days.

This past month, Rod Towers of the Gem, Lapidary, and Mineral Society of
Montgomery County, Maryland (the local club to which I belong) gave me a
holographic diffraction grating (6000 lines per inch), purchased from Edmund
Scientific.  The accompanying pamphlet (by Stephen Jacobs of the Optical
Sciences Center at the University of Arizona) lists the following emission
peaks for mercury: 577 and 579nm (yellow, a doublet), 546nm (green), 436nm
(blue), 365nm (lw uv), 313nm (mw uv), and 254nm (sw uv).



Date: Wed, 18 Apr 2001 22:16:59 -0700
From: Richard Bostwick <>
To: William Mattison <>
Subject: Re: FrOg On-Line #2001-03.

Regarding Chris's observation about the "fluorescence" of Franklin monazite:

1) According to Sterling Gleason, who gives Murata and Bastron of the USGS
credit for the information, monazite does not fluoresce under shortwave UV but
is selectively reflecting the green light emitted by the unfiltered Hg arc.
(Gleason p. 196)  This is confirmed in the "Henkel Glossary" in the monazite
entry on p. 57 in the brackets which indicate placement of the information by
the editors, Pete Modreski and Earl Verbeek. I have seen the phenomenon (though
I have not had a chance to confirm it in Franklin monazite) and it certainly
looks like fluorescence.  However, the fact that one doesn't see green under
filtered SW is a clue.

2) Chris deserves a lot of credit for this observation, which confirms an
important diagnostic use of shortwave UV.  In other words, this is probably the
easiest way by far to identify monazite-(Ce) from Franklin - a very rare and
desirable mineral from that locality.  Thank you, Chris, for passing along that

Dick Bostwick  


Date: Sun, 13 May 2001 16:53:06 -0400
From: Doug Mitchell <>
Subject: Monazite "fluorescence"
To: William Mattison <>

Hi, Bill--
Chris Thorsten's report in FrOg On-Line #2001-03 used the unfiltered shortwave
UV test for monazite on a micro crystal in a Buckwheat Dump dolomite.  He
referred to the green "fluorescence" of the crystal under the unfiltered light
of a shortwave UV lamp.  According to "Ultraviolet Guide to Minerals", by
Sterling Gleason, this green appearance is not fluorescence, but rather a
colored reflection of visible light from the shortwave UV lamp. The UV lamp's
visible light has unusual spectral features that emphasize a green reflection
caused by neodymium, thus establishing the substantial presence of rare earth
elements.  Bastnaesite, and probably some other rare earth minerals, will react
similarly to this test.

Given this explanation, the test should work equally well if you put a piece of
glass or any UV absorbing material over the shortwave UV lamp.  This should
make the matter of UV protection simpler.

P.S. Please feel free to include this in a FrOg online.

3. "Subscriber" List

NJ   Larry Berger
NC   Alan Borg 
NY   Dick Bostwick
NJ   Mark Boyer
CA   Kevin Brady
PA   Bob Carnein
VA   Peter Chin          Peter.Chin@USPTO.GOV
NJ   John Cianciulli
NJ   John Corsello
CT   Denis De Angelis
CA   Fred Devito
FL   Sandra Downs
NY   Howie Green
MD   Gary Grenier
MN   Tim Hanson
NY   Tema Hecht
CA   Andy Honig
CA   Mark Isaacs
MI   John Jaszczak
NY   Carl Kanoff
NJ   Steve Kuitems
FL   Roy Lambert
NY   Donald Lapham
NY   Greg Lesinski
PA   Jay Lininger
PA   Mike Logan
CO   Peter Marikle
MD   Bill Mattison
CA   Dan McHugh
NJ   Dan McHugh Sr.
VA   Curt Michanczyk
CA   Doug Mitchell
CO   Pete Modreski
WA   Don Newsome
NJ   Jeff Osowski
AZ   George Polman
NJ   Nathan Schachtman
NY   Paul Shizume
MD   Steve Shramko
NJ   Dave Slaymaker
CT   Charles Sloan
CA   Jane Grover-Smith
CA   Kent Smith
NJ   Chris Thorsten
NJ   Jim Tozour
NJ   Earl Verbeek
PA   John Vidumsky
PA   Eric Weis 
NM   Dru Wilbur
VA   David Woolley
FL   Herb Yeates
CA   Wayne Young

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