FrOg On-Line #1999-04



Welcome to FrOg On-Line #1999-04, Tuesday, December 14, 1999.


CONTENTS
========

 1. Introduction
 2. Franklin Show Report
 3. Picking Table and Sterling Hill Newsletter
 4. The Glowing Future
 5. New Fluorescence?
 6. Collecting News
 7. Misc. News.
 8. Featured Specimen
 9. Acknowledgements
10. "Subscriber" List


1. Introduction
===============

These FrOg On-Line messages are assembled and edited on a nearly ten year old
PC.  As you might guess, it may not be "Y2K compliant".  I do not know if I
will be able to use the PC after December 31, though I believe that most
likely, I'll have no real problems.  But if I cannot, someone else will be
needed to take over as the FrOg On-Line editor.  Think about it, just in
case....

Not all FrOg subscribers are listed in the subscriber list at the end of FrOg
On-Line messages.  So if you wish to say something to all subscribers, please
e-mail it to me, and let me know you want it passed on to all FrOg subscribers.
If you want me to pass it on right away rather than including it in the next
regular FrOg On-Line, let me know.

When e-mailing me about an already published FrOg On-Line message, please do
not include the referred-to message.  If I'm not clear on what you're referring
to within the original FrOg On-Line message, I'll ask.

These FrOg On-Line messages are designed to be read using a fixed-width font
(an "i" or a "." takes the same amount of space in a line as a "W") in a window
that is 80 characters wide.  The messages will be readable with other fonts and
window widths, but they may not look as nice.

This is the last FrOg On-Line for 1999.  So I wish everyone a great holiday and
a glowing 2000.  Enjoy.....


2. Franklin Show Report
=======================

This report is based on the minutes of the October 16, 1999 FOMS board meeting.
The minutes were provided by Tema Hecht.

The attendance at the 1999 Franklin Show was about 2500 people, down about 580
from 1998.  Best guess as to the reason for the drop was the hurricane which
affected the region earlier in the month.

The show program listed thirty indoor dealers, three of them in the fluorescent
area.  In addition, there were 99 outdoor (Pond) dealers on Saturday, and 60 on
Sunday.

I was originally going to include the financial aspect of the show in this
report, but I ultimately decided it was inappropriate.  FrOg On-Line is an
independent, private "publication"; it is not an official publication or
activity of the Franklin Mineral Museum, the Franklin-Ogdensburg Mineral
Society, or the Sterling Hill Mining Museum.  Therefore, this "publication" is
not the appropriate place to publish such figures.


3. Picking Table and Sterling Hill Newsletter
=============================================

I received my fall/winter, 1999 Sterling Hill Newsletter yesterday (Monday,
December 12).  Foundation members: if you have not yet received your copy, it
should arrive any day.

According to Dick Bostwick and Tema Hecht, the printer did not do an acceptable
job printing the 1999 Picking Table, so it was sent back to be re-printed.  It
is hoped the re-print will be done by this Friday (December 17), but no
guarantees.


4. The Glowing Future
=====================

Saturday, April 29, 2000: Trotter Dump collecting.  See the following extract
from Doug Mitchell's FMS Online:

     Date: Wed, 3 Nov 1999 13:57:50 -0500
     Subject: FMS118:desert meet,OR,cold,Langban,cheapUV
     Sender: Doug Mitchell <DMitchell@compuserve.com>

     [...]

     -------------------------------------- Trotter dump collecting
     >From the "rockhounds" and "rocks-and-fossils" mail-lists comes news of
     a second chance at collecting on the Trotter dump in Franklin, New
     Jersey.

     Subject: Trotter Dump & Sterling Hill, NJ, April 29 & 30, 2000
     Date:    31-Oct-99 at 17:58   
     Via:     rocks-and-fossils@world.std.com, rockhounds@drizzle.com     

     If interested, please reply to mailto:trotterdump@yahoo.com

     Greetings all, and once again if I may take a moment, it's time to
     prepare for next year's action packed weekend in Franklin, New Jersey,
     USA.  For those who were with us last year, there have been a few
     minor changes--we are only doing Trotter Dump on Saturday this year.
      The management of the Sterling Hill Mining Museum would like to host
     everyone on Sunday.  While Sterling Hill is an active museum and dig
     site, the Trotter is a closed location and is only open once per year.

     This is the only weekend of the year when you can dig at Trotter,
     Buckwheat, and Sterling Hill--in addition, you can see the museums,
     attend the weekend NJESA/FOMS/SHMM show, feast at the banquet, and bid
     at the auction--if you arrive Friday night the excitement does not
     stop until Sunday afternoon!

     The text of the brochure is below.  I apologize for the length;
     however, this is the only time I will post the entire text to these
     lists.  I may make a few more short announcements between now and
     April.  This year I am not holding a go/no go deadline.  I will
     simply post the $2,000 deposit myself for the facilities fee &
     equipment rental, and I will take reservations up until the end. 
     However, as the sole coordinator for the trip, I implore folks to
     reserve space as early as possible so I can send you maps, hotel
     info, mineralogical info, and trip updates.  

     Thanks again for your time, and now the brochure . . .

     ---------------------------------------------------------

     Trotter Dump! Sterling Hill!
     Franklin & Ogdensburg, New Jersey

     April 29 & 30, 2000            

     in conjunction with the NJESA/FOMS/SHMM Spring Show!

     The Delaware Valley Earth Science Society (DVESS) and the North East
     Field Trip Alliance (NEFTA) invite you to share an international
     collecting experience.  Last year, this field trip attracted dedicated
     collectors from across the globe.  Be one of them this year.  Read the
     following terms, then contact the coordinator below to reserve your
     spot
     . . .

     1. The facilities fee shall be $20 per person for all day and night
     Saturday.

     2. Collecting hours are from 9:00 AM to 7:00 PM, and 7:30 PM to 11:00
     PM.
  
     3. The daylight collecting fee is $1 per pound.  The Saturday night
     fee shall be $2 per pound from 7:30 PM to 11:00 PM.  The total limit
     for the day is 300 lbs.

     4. The owner shall provide running water, rest room facilities, a dark
     room, electricity, a snack bar, a bulldozer, and tools for sale.  UV
     lights are available for purchase at the Franklin Mineral Museum & the
     Sterling Hill Mining Museum.

     5. All collectors must carry liability insurance that covers damage to
     the property, such as the insurance offered by the EFMLS to its
     affiliate clubs.  Your club must co-sponsor the trip in order to be
     covered by Federation policies.  (Collectors may join the DVESS if
     they have no other means of proper insurance.  Proof of personal
     liability policy is also acceptable).  Collectors enter at their own
     risk and sign a hold-harmless liability waiver.

     6. Standard Federation safety rules apply-safety goggles and
     substantial footwear mandatory (no sneakers or sandals); gloves
     strongly recommended; children under 9 years not permitted. 

     7. All collectors are responsible for their own transportation and
     lodging arrangements.

     8. A minimum of 100 collectors is required.  Attendance is by advance
     reservation-please do not delay!  If you are staying overnight, the
     hotels fill up quickly, so reserve early!

     9. Participants also receive a coupon good for $1 off admission to the
     Sterling Hill Mining Museum on Sunday!

     10.  We will also dig at Sterling Hill on Sunday: 9 AM - 3:30 PM, $1
     per pound.  There is a $10 admission fee which applies to the first
     ten pounds; $1 per pound thereafter.

     If this sounds like an opportunity you don't want to miss, send an
     SASE, proof of insured club affiliation or proof of personal
     liability insurance, and a check for $20 per collector made out to
     DVESS to

     Don Halterman
     1708 Ralston Drive
     Mount Laurel, NJ 08054-3351
     609-231-4342
     trotterdump@yahoo.com                                      

     Please give an e-mail address if you have one.  You will receive an
     information kit either by USPS or by e-mail.

     "You never know what you'll find!"

     [...]

As I just learned late last week, the FOMS does not have monthly meetings in
December, January, and February.  Dick Bostwick told me by e-mail that an FOMS
program for spring 2000 "will be mailed to FOMS members on or around March 1.".
I will publish information here in FrOg On-Line also soon after I have it.

According to the summer 1999 issue of the Sterling Hill Mining Museum
Newsletter, the museum is open the week between December 25 and January 01, and
weekends.  Other times are by appointment only.  I will publish information
here in FrOg On-Line soon after I have it.

According to the September 1999 issue of the Franklin Newsletter, the museum is
closed until March 04, 2000.  No events or collecting are scheduled before
then.  I will publish further information on next year's events in the next
FrOg On-Line.


5. New Fluorescence?
====================

Earlier this year, Claude Poli showed me a specimen he had collected from the
Buckwheat Dump.  He pointed out areas fluorescing a mix of pink-orange(?) and
bluish gray.  This was at the time believed to be an apatite group mineral
fluorescing two colors much as some FrOg Sphalerite fluoresces both blue and
pink-orange.  During the Franklin Show, Chris Thorsten found a few more
specimens with this "apatite".  I bought three from him.  The first specimen
consists of a Calcite layer, a very thin garnet layer, a layer of this
"apatite", and a layer of what was thought to be Hyalophane.  The second
specimen, which I will not describe in detail at this time, consists of
Calcite, this "apatite", Microcline, Quartz, garnet, and other at the time
un-identified minerals.  The third, which I will not discuss in detail at this
time, consists of Microcline, Calcite, what was thought to be "apatite" but
fluorescing pink in this case, Calcite, Willemite, Scheelite?, Hematite?, and
garnet.  When I got home and examined the third specimen more carefully, I
concluded its "apatite" was probably scapolite.

In mid October, I brought the first two specimens back up to Franklin to dunk
in the liquid nitrogen during the FOMS meeting.  The day before the meeting, I
showed them to John Cianciulli so he could confirm my mineral identifications.
He was skeptical of the "apatite" in both specimens, and the Hyalophane in the
first.  He asked me to bring them back to him after the meeting so he could
get chips off them for optical identification.  I did; he got the chips.  The
chips off the first specimen were labelled "wcm1"; the chips off the second
were labelled "wcm2".

The first specimen is shaped roughly like a quarter of a frosted two-layer
circular cake about 5 cm thick and about 6.5 cm in radius.  In natural light,
the top "frosting" is a nearly opaque white granular matrix which I thought to
be Hyalophane.  Embedded in the crust are nearly opaque dark green grains
(identity unknown), and numerous very small translucent pale gray grains
(identity unknown).  This "frosting" is about 5 mm thick.  The matrix mineral
fluoresces a rather weak reddish violet under short wave ultraviolet.  The next
layer (the upper layer of cake) is about 1 cm thick and consists of a mixture
of medium-pale gray and medium-dark gray small grains.  Under short wave
ultraviolet, these fluoresce pale lilac (a little weaker and very slightly more
blue than typical Kipawa Complex Agrellite) and bluish gray.  The third layer
(the frosting layer between the cake layers) is only a few millimeters thick,
and consists of essentially massive dark amber garnet.  The garnet is solid at
the boundary with the fourth layer and penetrates into the "apatite" cake
layer.  The garnet is not fluorescent under short wave ultraviolet.  The bottom
cake layer (getting hungry?) is about 2.5 to 3 cm thick and consists of
translucent rather pale gray Calcite.  The Calcite fluoresces a moderately
bright orange-red under short wave ultraviolet.  John took the "wcm1" chips
from the reddish violet fluorescing mineral in the top frosting layer of this
delicious rock.  Here are his surprising results, based on optical analysis:

     Date: Wed, 20 Oct 1999 14:44:07 -0400
     From: John Cainciulli <u1008042@warwick.net>
     Subject: unknowns wcm1 & wcm2

     Dear Bill,
              I checked both samples carefully.  wcm1 is quartz!  wcm2 is
     scapolite (bl. and orange-yellow fl. S/W), sphalerite (nfl.), calcite
     (red fl.), and serpentine.  Absolutely no fluorapatite present!
                                     Glad to be of service to you
                                                     JC

I checked Pete Dunn's monograph, the fluorescent "list" in the program for the
1999 Franklin Show, Robert Jones' book, and both of Manuel Robbins' books, and
found no hint of Quartz from Franklin fluorescing reddish violet.  So we now
have a new Franklin Quartz fluorescence!  This may also explain the absence of
fluorescence brightening when the specimen was chilled.  Under short wave
ultraviolet, Franklin Hyalophane has a rather weak red-violet fluorescence at
room temperature that brightens and reddens substantially when sufficiently
chilled (the effect is easily seen at -20 degrees Fahrenheit).  But with the
top frosting layer of this specimen being identified as Quartz rather than
Hyalophane, the absence of fluorecsence brightening when chilled is now
understandable.

It is my understanding there are two other specimens from the original rock:
Chris Thorsten has one, and Claude Poli has one.

Although sample "wcm2" is from a different specimen, based on the similiar
natural light appearance and fluorescence of the top cake layer (what was
believed to be apatite) of the first specimen and the sampled mineral from the
second specimen, I believe the apatite layer to be mainly scapolite rather than
apatite.

Now I'm really hungry.  Excuse me for several minutes while I get me some
homemade strawberry pie and a flaming mamie (a flaming cherry sundae).


6. Collecting News
==================

Two collecting reports on the Saturday, November 06 Buckwheat Dump night dig
were received by e-mail.  Here they are:

>From Chris Thorsten:

     Date: Fri, 12 Nov 1999 09:24:56 -0500
     From: Chris <chris@atomic-pc.com>
     Subject: Re: Buckwheat night dig.

     Hi Bill,

     Here it is... Buckwheat night dig report:

     The surface of the dump glowed orange with spots of green as the UV lamps
     searched over it.  I moved slowly and tended to stay in one area, and it
     wasn't such a bad idea: first, a piece of brightly-fl. calcite with a thin
     vein of fluorescent sphalerite revealed itself... a nice remnant of our
     daytime digging.  Needless to say, that went in my bucket.  I also found a
     rock that, when split open, revealed a penny-sized blotch of fluorapatite
     having "peach" fluorescence, accompanied by willemite and calcite in a
     dense ore & garnet matrix...  though no one else got that excited about
     the piece, I was pleased to find this combination on the Buckwheat.

     There were a few hand-sized pieces of calcite, left over from our daytime
     digging, that had nice two-toned fluorescence, almost like "crazy
     calcite".  Under SW UV they had blotches of orange-red scattered across a
     backdrop of deeper reddish... really nice stuff.  In the same area of the
     dump were some good hydrozincites, but they were too large to cart away,
     seeing how they were attached securely to massive dolomite boulders.
     
     However, my best find came from a boulder that was wedged in between
     several other boulders, one which I wasn't sure I could extract from its
     hiding spot.  This sneaky boulder was hiding cleverly enough that everyone
     else had missed it... but I saw it, or maybe I smelled it...

     I'd left my prybar with the hand truck and didn't feel like getting it, so
     I took a "careful" swing with the 20-lb sledge (as careful as you can *be*
     with that thing, anyhow) and off came a big chunk with a thick vein of
     willemite and hardystonite running through the calcite... it was occasion
     for some delighted cuss words of surprise... with fogged-up goggles I
     prepared to trim my prize with a hammer and chisel (it was quite heavy at
     first... probably 40+ lbs, mostly of uninteresting franklinite / calcite
     ore rock).

     With careful trimming, I ended up with a couple of good-size specimens,
     each with the willemite & hardystonite vein centered in the calcite,
     making great 3-color pieces.  I was happy enough that I didn't care
     whether I found anything for the rest of the night (I did find some stuff,
     but not nearly as good as this).

     My haul for the night consisted of 27 lbs of rock, most of which was
     thanks to the aforementioned specimens of willemite / hardystonite /
     calcite / franklinite.  Did I mention that franklinite is heavy?  It took
     me forever to get to the top of those Buckwheat stairs, huffing and
     puffing, but I left being one happy collector!

     -Chris Thorsten

>From Mark Boyer:

     From: mark boyer <mboyer@pace2001.com>
     Subject: RE: Buckwheat night dig.
     Date: Fri, 12 Nov 1999 18:23:09 -0500

     Bill:

     I found some odd two-tone calcite, or possibly calcite in feldspar, but I 
     need to do some testing.  It has bright, classic calcite orange-red
     patches and grains in a darker orange-red matrix.  Also found a nice piece
     of sphalerite.  Talk to Chris--he found some nice hardystonite (!), of
     which I got a piece.

     Mark

Both John Cianciulli and Claude Poli reported by phone that the best apatite +
Fluorite var. Chlorophane pieces ever found there were found that night.
Claude also reported a two-tone Calcite (similiar to "crazy" Calcite), Albite
(fluorescing blue) and some other reddish fluorescing mineral (a feldspar?),
and what he referred to as "step Willemite".


7. Misc. News
=============

Chris Thorsten writes:

     Date: Tue, 12 Oct 1999 04:40:18 -0400
     From: Chris <chris@atomic-pc.com>
     Subject: fluorescent mineral site update

     Hi everyone,

     I just wanted to let you know that I've started updating my mineral
     collecting site again.  I've added some nice new photographs of recent
     finds... check out
          http://members.xoom.com/njminerals/photos.html

     Of course, I've tried to keep the information on the mineral pages as
     accurate as possible, but it will be subject to constant fine-tuning as I
     learn more.  If there's anything that screams out to be changed or
     corrected, now's the time to tell me.

     I have more photos on the way, too, so keep checking back.

     Sincerely,
     Chris Thorsten

I not only checked out his photos, but also some of his other web pages (just
follow the links built into the page he directs you to in his message above).
They make for some interesting reading.

Many readers already know that earlier this year, Gary Grenier sold one of his
collections.  In a message to me about this, he has some interesting, thought-
provoking thoughts (ummm, well, how would y-o-u word it?!), which I believe
ought to be shared.  So here goes:

     Date: Mon, 18 Oct 1999 12:20:00 -0400
     From: ("GARY WGG WILLIAM G  GRENIER JR ") <William.Grenier@mercantile.net>
     To: (William C Mattison) <mattison@thunder.nws.noaa.gov>,
             rbostwick@spexcsp.com, rbostwick@spex.com, Peter.Chin@USPTO.gov

     Bill:

     Good question, and you are partly on the mark.  My family needs have far
     out-weighed my collection needs and capacity to house and maintain the
     3,600 specimen collection which I have considered these past 5-years as
     "finished".  In fact, I have had the 3,100 specimen, or bulk of the
     collection in storage for years at $200 a month.  My priority is family,
     and I have my mother and mother-in-law to take care of in a growing
     capacity.  Thus, my decision to sell the collection seemed reasonable and
     appropriate since the likely hood of displaying it and properly studying
     and curating the collection was just not likely to happen by me - no time
     or place.

     Collecting Franklin rock all of my life is more than a hobby, it is a
     passion that does not stop with one collection.  In fact I have created
     over 10 different Franklin collections and through the years have sold 3
     of the ten that I assembled.  In each case I found more enjoyment in
     recognizing the completion of assembling a collection and latter letting
     it go.  The reason for letting it go has always been so I could start a
     new collection on a different approach or speciality.  In each case, I
     have been fortunate and rewarded with a higher level of collecting success
     when I started a new collection.  So, I do not look at this as an ending,
     rather a growth process into a new collection.  I am still collecting
     Franklin!

     The advantage of letting it go all at once is not to me, rather it is to
     the Franklin community who will have a chance to own more Franklin and
     Sterling Hill specimens as Steve Philips sells off what he does not need
     for his own collection.  In my own way I am trying to give back to the
     Franklin community something that every collector needs... a chance at a
     good rock from time to time.

     It is ok to share this if you like...

     Thanks for your concern Bill, it is appreciated.

     Gary Grenier
     Compliance Officer
     Network Administrator
     Citizens National Bank

     ------------------( Forwarded letter 1 follows )--------------------
     Date: Mon, 18 Oct 1999 12:37:57 GMT
     To: william.grenier
     From: William.C.Mattison[mattison]@thunder.nws.noaa.gov.SMTP
     Subject:

     Gary,

     Are you and your family ok?

     I heard more than once this past weekend up in northern NJ that you sold
     your collection to Steve Phillips.  Such actions are sometimes because of
     sudden serious financial need, such as family medical emergency.  Thus
     the above question.

     Bill.


8. Featured Specimen
====================

                                  Minehillite
                                  ===========


                                      By

                                John Cianciulli

                Minehillite (K,Na)2-3Ca28(Zn4Al4Si40)O112(OH)4

                        Margarosanite Pb(Ca,Mn++)2Si3O9


Minehillite was first described by Dr. Pete J. Dunn in 1984 [Dunn 1984].
Minehillite was found only in the Franklin Mine, Franklin, New Jersey.  It was
not found at Sterling Hill.  It still remains one of the unique minerals of
Franklin.


                                 INTRODUCTION
                                 ============

My first experience with this mineral was in 1980.  I heard a rock shop was
moving to a smaller location and the owner was having a special sale.  Not
really expecting to find much Franklin-Sterling material, I paid a visit to
this rock shop (Crystal Gems) to check out this material.  The owner of this
shop was a man named Paul Hansen.  I later learned Paul was formerly a business
partner of Mr. Charles Keye.  Paul rarely if ever had Franklin-Sterling rocks
for sale in the shop.  But when I asked him if he had any Franklin rocks for
sale he smirked and said "I have a couple of tons of grunge from there."  Paul
let me go through some of the boxes behind the counter where I saw a lot of
Sterling Hill North Ore Body material and a little Franklin willemite etc..  I
found a specimen on the first pass that looked like a platy margarosanite from
Franklin.  When I finished picking through the boxes and presented my choices
to Paul, he took one look at the "pearly-white platy" specimen and said "that's
not from Franklin, that's apophyllite from South Carolina!"  He did not want to
charge me for the specimen.  He finally agreed to accept $5.00 for the
specimen.  I paid him the five bucks and left for home feeling overwhelmingly
gratified that I just landed the best "margarosanite" I ever held in my hand.
When I got home I was a bit disappointed with the weaker fluorescent response
this specimen had compared to other platy margarosanites I had seen.  I was
still convinced this was a killer-crystallized margarosanite!

A couple of years later I exhibited this specimen at the Franklin Show as one
of the "first described" mineral species (still thinking it was margarosanite).
During the show Dr. Pete J. Dunn expressed an interest in taking a closer look
at this specimen.  I was happy to oblige in the name of science and out of
sheer curiosity.  Pete took the specimen back to the lab and a few days later
he called with the news that this specimen was a well-crystallized example of
an as yet unnamed new mineral species from Franklin, NJ.  Because of the
significance of the specimen I donated it to the Smithsonian.  That was nearly
16 years ago.  My prized "margarosanite" was in fact the new mineral
minehillite!  For years I looked for another crystallized specimen like that
one to no avail.  Although there was plenty of minehillite available for sale,
much of it was and still is questionable.  Most of the material that was
available was associated with fibrous wollastonite, pink grossular garnet,
vesuvianite and gray feldspar (probably microcline) and margarosanite.  The
material I first encountered occurs as thick aggregates of platy pearly
crystals on a gray feldspar (the feldspar resembling dolomite at first glance).
I have seen brilliantly fluorescing margarosanite that look identical to
minehillite on gray feldspar at arms-length.  Nick Zipco has two splendid
examples of this, one of which has a 3cm diameter complete spherule of
wollastonite attached to it.

In the early '90's Andy Massey acquired some material that resembled
crystallized minehillite.  The smaller thumbnail size pieces he showed me were
indeed minehillite but the larger pieces that appeared similar were brilliantly
fluorescent casting doubt in my mind as to their true identity.  Needless to
say, all of this material was sold as "minehillite" without further ado.  At a
later time, Andy showed me an interesting specimen of salmon calcite with
crystals of margarosanite on one-side and minehillite crystals on the other
(confirmed by optics).  The sample was little bigger than a golf ball yet
different than other minehillites I had seen to date.  I expressed an interest
in acquiring the sample for the museum's reference collection.  I was told the
specimen was not for sale although Andy let me have a few flakes from both
sides for optics.  About two weeks later I heard from a collector the specimen
was being offered for sale for over $1,000.00.  A couple years later, much to
my delight, I found a huge chunk of this material in the museum fluorescent
exhibit (24x15x9 cm).  I will describe this specimen later.

Several years ago the Franklin Mineral Museum acquired the remainder of the
Adam Szenai collection.  There were some nice mine run Franklin mine specimens.
Two of his specimens were standouts.  One was a large gem willemite crystal,
and the other was a thick mass of minehillite crystals on gray feldspar.  This
specimen is the twin of the one that reposes in the Smithsonian collection.
The Adam Szenai piece is on display in the local room of the Franklin Mineral
Museum.


                                 OBSERVATIONS
                                 ============

Minehillite can be and often is confused with margarosanite (with which it
often occurs), prehnite (because of its platy appearance), and hardystonite
(because of the fluorescence).  I have studied the various forms of minehillite
and have made observations that, in my opinion, have significant diagnostic
value.  Optically, minehillite is uniaxial, negative, with w = 1.607 and e =
1.604.  Margarosanite is biaxial, negative, with a = 6.27, b = 1.771, and y =
1.789.  Prehnite is biaxial, positive with a = 1.617, b = 1.625, and y = 1.643.
Hardystonite is uniaxial, negative, with w = 1.669, and e = 1.657.  Minehillite
plates or crystals very often have inclusions of native lead that cause some
crystals to appear to be shiny black.  These inclusions are easily observed
under the polarizing microscope and may also be observed under a regular
microscope using transmitted light.  Minehillite does not accept lead, leaving
it behind as a separate entity.  Something like trying to mix oil and water.  A
barely discernable light-yellow coating (probably due to weathering) frequently
coats crystal masses relatively free of unwanted lead appearing pearly-white.
This has been observed on crystallized masses on gray feldspar.  Most specimens
of minehillite are too messy for this to be observed.

In the absence of optical data, fluorescence is a strong diagnostic tool for
distinguishing minehillite.  Thanks to Greg Anderson from San Diego,
California, the Franklin Mineral Museum now owns a mid-range UV lamp.  The
mid-range lamp is proving to be a valuable diagnostic tool.  Minehillite is
reported to fluoresce violet short wave.  This response is observed universally
among those samples that have been examined.  Under long wave, I have observed
a poor response as has been reported to fluoresce weak violet [Dunn 1995].  The
mid-range response of minehillite will dazzle you!  Under mid-range minehillite
fluoresces bright blue to strong violet.  The mid-range ultraviolet lamp will
facilitate distinguishing minehillite from margarosanite from mixtures of the
two, the most commonly seen minehillite specimens in collections.  These
specimens occur with fibrous wollastonite, grossular, and vesuvianite.

If you have seen minehillite in what appears to be a variety of habits, you may
draw the erroneous conclusion as I did early on that there are probably several
different paragenisis for minehillite.  Dick Bostwick's earlier observation (1)
was right!  There is only one paragenisis for minehillite!  We have seen the
mixture with wollastonite.  Some of us have seen beautiful platy crystals
encrusted on gray feldspar where the feldspar fluoresces dull to medium red.
Few of us have seen crystals of minehillite and margarosanite on salmon
calcite.  In the Spex/Gerstmann collection reposes a colossal specimen, which
solves the puzzle, or should I say, connects all the above described
minehillite specimens into one paragenisis.


                                  S/G # 1657
                                  ==========

24x15x9 centimeters in size, this specimen was identified as "margarosanite"
and cataloged as such.  The margarosanite occurs as large platy crystals up to
1.5cm.  Minehillite occurs as 1mm crystals and are scattered about the edges of
the margarosanite.  A distinct zone of native lead surrounds a pod of gray
feldspar.  The pod is 4x5cm.  The lead is part of a reaction zone containing
minehillite around the feldspar that is in contact with margarosanite on one
side and what appears to be aggregates of 3 mm size grains of augite (?) on the
other.  A small part of this zone is in contact with pink grossular that has
dark-red vesuvianite inclusions.  The augite (?) occurs between the reaction
zone and a bright red fluorescent salmon color calcite.  The rest of the matrix
is also quite interesting.  It appears to be a random mix of pink grossular,
dark red vesuvianite, diopside, pods and zones of feldspar (microcline?),
augite grains (?), minor amounts of fibrous wollastonite (fl. orange-yellow),
and fluorapatite, blue-green in white light (fl. dull orange s/w).  There is
also present serpentine on a slik-n-side surface.  The margarosanite fluoresces
under short wave, bright pale blue violet, overwhelming the more subdued
fluorescence of minehillite (violet).  Long wave, the margarosanite fluoresces
dull red and the minehillite a barely discernable violet.  Mid-range is like a
magic show!  The minehillite fluoresces brighter violet, and the margarosanite
displays no hint of its typical short wave response blue-violet.  It fluoresces
bright red-orange with light to medium orange streaks that are also somewhat
overwhelmed by the bright red-orange color.


                                  CONCLUSION
                                  ==========

There no longer has to be a sense of ambiguity about minehillite.  The
mid-range ultraviolet lamp is just another tool to beat ignorant or
unscrupulous dealers at their own game.  Of the likely candidates, minehillite
has a unique and distinctive response to mid-range ultraviolet as does
margarosanite.  Hardystonite has little or no response mid-range and prehnite
can be ruled out by its short wave response.  Minehillite, though more common
at Franklin than first thought, is still a very rare mineral.  Aggregates of
large platy crystals on gray microcline are extremely rare and are often
confused with margarosanite.


                                  ASSEMBLAGE
                                  ==========

                  Calcite CaCO3 (manganoan)

                  Fluorapatite Ca5(PO4)3F

                  Wollastonite CaSiO3

                  Margarosanite Pb(Ca,Mn++)2Si3O9

                  Diopside CaMgSi2O6

                  Microcline KAlSi3O8

                  Grossular Ca3Al2(SiO4)3

                  Vesuvianite Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4

                  Augite (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6

                  Minehillite (K,Na)2-3Ca28(Zn4Al4Si40)O112(OH)4 *

                  Lead Pb *

                  *last to form in this assemblage


                                  References
                                  ==========

Dunn, P. J., Peacor, D. R., Leavens, P. B., and Wicks, F. J.
1984
Minehillite, A New Layer Silicate from Franklin, New Jersey, Related to
Reyerite and Truscottite.
American Mineralogist, vol. 69, pages 1150-1155.

Dunn, P. J.
1995
Franklin and Sterling Hill, New Jersey: the world's most magnificent mineral
deposits.  Part Four, pages 501-502.

-------------------------------------------------------------------------------

(1) "editor's" footnote: I asked John about "Dick Bostwick's earlier
    observation".  He told me this refers to a private conversation between
    himself and Dick sometime in the mid 1980s, shortly after Minehillite was
    recognized as a new species.


9. Acknowledgements
===================

First and foremost, I'd like to thank John Cianciulli for the "Featured
Specimen" article.  I asked him earlier this fall to send me a description of a
smallish Minehillite specimen he showed me some time ago.  As you saw, he went
the extra mile and submitted an excellent article well beyond what I requested.

I thank Chris Thorsten and Mark Boyer for their contributions, John Cianciulli
for the optics on chips from two of my specimens, Tema Hecht and Claude Poli
for information used in this issue, and Dick Bostwick, John Ciancuilli, and
Steve Kuitems for their advice on this issue's contents.


10. "Subscriber" List
=====================

NJ   Larry Berger        lberger@interactive.net
NY   Dick Bostwick       rbostwick@worldnet.att.net
NJ   Mark Boyer          mboyer@pace2001.com
CA   Kevin Brady         kbrady@cslanet.cals
PA   Bob Carnein         ccarnein@eagle.lhup.edu
VA   Peter Chin          Peter.Chin@USPTO.GOV
NJ   John Cianciulli     rockman@warwick.net
MD   Gary Grenier        william.grenier@mercantile.net
MN   Tim Hanson          tim@ens.net
NY   Tema Hecht          thecht@worldnet.att.net
     John Jaszczak       jaszczak@mtu.edu
NJ   Steve Kuitems       skuitems@eclipse.net
     Jay Lininger        matrix@redrose.net
PA   Mike Logan          mikelogan@sprintmail.com
MD   Bill Mattison       mattison@thunder.nws.noaa.gov
CA   Dan McHugh          dmchugh@eee.org
CA   Doug Mitchell       DMitchell@compuserve.com
CO   Pete Modreski       pmodresk@usgs.gov
WA   Don Newsome         uvsystems@aol.com
AZ   George Polman       polmans@compuserve.com
NJ   Nathan Schachtman   nschacht@voicenet.com
NY   Paul Shizume        s1153fam@aol.com
NJ   Dave Slaymaker      dh10000@yahoo.com
NJ   Chris Thorsten      chris@atomic-pc.com
NJ   Jim Tozour          jtozour@home.com
NJ   Earl Verbeek        everbeek@nac.net
     Herb Yeates         herb@simplethinking.com             Japan

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