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                           Mineral of the Month--February

                              Pennsylvania Fluorite

                                              Calcium Fluoride


                                        "Pennsylvania Fluorite"

                                              By Ken Casey

Why Pennsylvania Fluorite?
A Rare Treat:Kerry Matt Photos
Chemistry & Science
Pennsylvania Fluorite Geology
Mineral Associations
Geologic Age
Predominant Fluorite Colors
Two Museums of Note
Members' Gallery
Article Contributors
Photo & Graphics Credits
Suggested Reading
Invitation to Members
Past Minerals of the Month

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        Pennsylvania State Flag

Image courtesy of Marchex, Inc.
©2007, World Flag Database

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What's in our own backyard?!...


...why Pennsylvania Fluorite, of course!

(Top, left): Purple Fluorite & Pink Dolomite, Binkley-Ober Quarry, E. Petersburg, PA
Photo by Ken Casey ©2007

(Top, right): Purple & Green Fluorite, New Paris, PA
Photo by Ken Casey ©2006


     This month, we explore in our own backyard: Pennsylvania Fluorite.

     Well, we've been around the world on our quest for noble Fluorite.  Yes, it's time to come
home.  So, let's find out what's in our own backyard!  Everyone, everywhere, please join us! 
Let's go!



     Welcome back to our newest installment of Mineral-of-the-Month! 

     Now in colder February, our journey will take us through the southeastern and central parts
of the Keystone State: Pennsylvania!

     You might be saying, 'Ken, are we visiting Fluorite yet again?!'  I would answer, 'Yes, of course. 
Except this time, we are going in depth to local Pennsylvania locales.'  So, if your game to follow
the theme of our club's March 3-4, 2007 Show, please do trek with us.  Enjoy!


Why Pennsylvania Fluorite?

     Why, look at all of the locales we might procure some from!  One could spend an entire season
or two of collecting to free these beauties from their host quarries.  Check out the map below:

pennsylvania_map_outline_counties_fluorite_locales_original3a.gif (96028 bytes)Map of Documented Fluorite Locales in Pennsylvania from many sources (Ken Casey)

     Within a 2,000 square mile area alone for searching, an avid rockhound could devote an entire
career to discovering or writing about this month's favored mineral.  As you could tell by now, this
author is keen on Fluorite, especially those found in our backyard. 


A Rare Treat

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     As a rare treat, I'd like to share with two photos of some extremely nice specimens of purple fluorite from the Burkholder Quarry.  The mine section from which these phenomenal rocks came has already been mined out.  These masterful photos were taken and shared by our new friend, Kerry Matt.

     Kerry is a member of the Central Pennsylvania Rock & Mineral Club of Harrisburg, PA.

Kerry Matt (left) shows his new book at our show Photo by Ken Casey

     Kerry has written a book on Pennsylvania Minerals, called Pennsylvania's Rainbow Under Ground
Well it's here, along with two other related works!  Check it out:


Kerry Matt’s Books

Books are ready and available. It is possible to acquire them via Kerry’s e-mail. You’ll have to ask him about shipping costs to your area.

Pennsylvania's Rainbow Under Ground $80.00 each. It’s chock full of color macro specimen photos; comes with CD [includes 200+ additional pages, about 440 pages in all!]

Pennsylvania Paleozoic Playground (fossils) $40.00 each. This book covers the major fossils found in PA in a more general or basic level. (limited Self printed spiral bound with lamin-a cover) or on CD at $16.00 each.

The Lower Cambrian Explosion of life in my back yard (fossils) $30.00 each. This one focuses entirely on the local material here in the Lancaster area. It is a detailed report on fossils pre-dating the famous Burgess, all of which I document on personal level of experience from local excavations. (self-printed spiral bound with lamin-a cover) at $30.00 each (limited print). And CDs at $16.00 each.

He also has a few Pennsylvania Paleozoic Playground that are un-edited at -$10.00 discount.


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Purple Fluorite Cubes on Quartz
Burkholder Quarry,
Lighter Purple Fluorite crystals
Burkholder Quarry,
Photos by and courtesy of Kerry Matt ©2007


Chemistry & Science

     We know the basic chemistry of Fluorite.   We know it's chemical name and formula: Calcium
Fluoride, CaF2.  From our basic chemistry, we discern that Calcium (Ca) is a cation, and Fluorine (F)
is the anion.  In the hydrothermal solution process, Calcite (CaCO3) gives up its carbonate anion, or
its CO3, in exchange with the highly reactive Fluorine (F) anion, hence, CaF2.   Other elements may
play a role, but we'll keep it simple for now.

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Simplified Chemical equation for the formation of Fluorite  (Ken Casey)


Pennsylvania Fluorite Geology

     In Pennsylvania, the process is no different.  Though some propose artesian meteoric groundwater
as the mechanism, and others proffer a hydrothermal formation process, the general ionic exchange is
relatively the same.  Let's explore some of the mysteries of Pennsylvania Fluorite!  

     In underlying ancient limestone strata, vugs and cracks hide pristine cubes of gemmy purple
fluorite!  If we could dig these natural wonders from the surface by hand, we would have hit the
motherload of all PA fluorites.  However, in most all cases, we can only obtain rare, undamaged
specimens by support of the local mining process: open pit quarries.  Thanks to them, their benches
and spoil piles paint a geological view over millions of years in their freshly-cut cross-sections. 
Pre-fractured boulders are now open to our hunting gaze and accessible with our collecting tools.

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Two examples of well-formed, gemmy purple Fluorite cubes fresh from Kurtz Quarry
Courtesy of DMS Member Joe Meloney
Photos by Ken Casey

     As 'quarrying' means 'the removal of useful host rock' generally, we collectors actually 'mine' for
specific ore, such as pyrite, dolomite, calcite, and our fluorite.  Our club state of Delaware has no
limestone quarries, yet nearby Pennsylvania boasts scores of them.

(See Above: Map of Pennsylvania Fluorite Locales)

     Though there are no known fluorite locales in Delaware near our clubhouse at Greenbank Mill,
Price’s Corner, it remains to be found just 30 miles or more away in Lancaster County, PA.  Since we
were once considered the "Three Lower Counties" of Pennsylvania, before Delaware became the First
State, I believe our bond with our neighbors in the Commonwealth still holds strong from colonial times. 
(Yes, I still do remember some of my 4th-grade Delaware History.)

     Honing in on our quarries, let's visit their geology first.  Then, we'll take a photo tour of some
amazing specimens collected by our club members and friends.

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Igneous dike intruding into limestone layers DMS Fieldtrip, December 2, 2006
Photos from Burkholder Quarry by Ken Casey

     Pennsylvania Fluorite can be found in the eastern and south-central regions of the state,
according the Pennsylvania Geological Survey.  It has usually formed in the area’s limestone and
dolostone (karst topography) under high-grade metamorphism by the movement of magma-heated, hydrothermal groundwater, which travels through brecciations in the host rock.  These natural cracks
play host to water with dissolved minerals and gases, the major constituents being calcium
carbonate and fluorine.

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Pennsylvania Regional Karst Map, Courtesy of DCNR, Pennsylvania Geological Survey

     Other minerals may be present, which could contribute to the fluorite-formation process. Calcium
and metallic cations, as well as fluorine anions shift bonds in a chemical reaction, which spurs the precipitation or growth of crystals.  Sometimes Magnesium plays a part.

     So, we commonly find fluorite crystals, in various stages of formation in calcite or dolomite veins
within the limestone/dolostone matrix.  It has also been found in the serpentine quarries of Chestnut
Hill, PA.

(Source: Lehigh University Digital Library Projects: PGS, 48 Pa. Acad. Sd. Proc., vol. XI, pp. 55-57, 1937.)

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General geology photos showing prominent formations of Burkholder Quarry (Ken Casey)

Mineral Associations

     Marcasite and pyrite are generally associated with eastern Pennsylvania fluorites.   South-central
fluorites are more likely to contain more and varied metal-sulfide mineral associations.

     Associated minerals to Fluorite in PA are: calcite, quartz, chalcopyrite, pyrite, sphalerite, hematite, goethite, hydrozincite, malachite, dolomite, graphite, millerite, etc.

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Kurtz Quarry from the top shelf in 2006 Joe Meloney's find-of-the-day from Kurtz, close-up
(Purple Fluorite, White Calcite, Clear Quartz, Pink Dolomite, Golden Chalcopyrite--all on limestone!)
(Photos by Ken Casey)

     When we get metal-sulfide mineral associations, the resulting crystals point towards magma-driven
events.  Whether from the heat of contact metamorphism in one stage, to the subsequent proliferation
of hot groundwater flows, our region of Pennsylvania's mineral wealth culminates in fine specimens of
our favored Fluorite.  Some superb multi-mineral vugs have produced display cabinet grade material!

     For example, a recent Binkley-Ober Quarry trip at the end of 2006 netted our club President,
Karissa Hendershot, a crystal assemblage of Purple Fluorite, Pink Dolomite, Yellow Barite, White
Calcite, and metallic Millerite needles--all in one specimen!

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Sloped folds of limestone layers Karissa's Millerite needles in dolomite Karissa's Yellow Barite in dolomite
The Binkley-Ober Quarry hosts limestone geology and some rare finds of fluorite-associated minerals
(Photos by Ken Casey 2006)

     We can't guarantee that you'll find this hot a rock when you join us, but it speaks to the quality of
finds we generally make over the quarry system each year.  So, please do come along as a member,
and enjoy club collecting.

Geologic Age

     Most of our Pennsylvania fluorites are found in Cambrian-Ordovician-aged limestone, faulted and
folded with intense deformation.  Limestone and dolostone layers can be see that vary in composition
of magnesium and silica, with varying crystalline types, and show differing color variations, from white
to pink to gray.  This doesn't mean that the variation of fluorites are that old, just the host rock.

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     The Lancaster County quarries that we visit as a club are officially part of the Lancaster Valley Section of the Piedmont Physiographic Province.  We collect from spoils dug from two rock units: The younger Epler Formation (485 myo) of the Lower-Middle Ordovician and the Buffalo Springs Formation (520 myo) of the Middle-Late Cambrian.


(Left): Geologic Map of Pennsylvania, Courtesy of the Pennsylvania Geological Survey

     Meckley's Quarry in Mandata, Northumberland County has massive purple fluorites of a different
age.  Its Silurian (443-417 myo) limestones of the Keyser Formation are found in white calcite and
heavy dark gray limestone.  When the landmass was a seabed, strontium-layering later contributed
toward its almost unique mineralization of Celestite, Strontianite, and Fluorite deposition.

     In comparison to the vastly popular Illinois fluorite locales of Mississippi/ Early Osagean age
(roughly 354-323 myo), our Pennsylvania specimen host rocks are grandly more ancient--and are
all the more prized for it!  Though their fluorites are measured at having formed 150-120 mya, our's
may be younger.


Predominant Fluorite Colors

     By this author’s research and experience, most Pennsylvania fluorites are purple, some having
some rare green also, like those of New Paris.  The PGS agrees: “Purple is the common color in Pennsylvania. Also colorless, white, green, blue, or yellow.”


     We'll study in-depth next month in "The Colors of Fluorite"Stay tuned!

     “In recent years both purple and green fluorite have been found in calcite veins in the Ormrod
quarries of the Lehigh Portland Cement Co. It is probably this same locality that furnished the
specimens analyzed and described by E. F. Smith in the following quotation: About one and a half
miles southeast of the above locality (Ironton iron mines) are the limestone quarries of Mr. Kieckner.
In them have been discovered veins of beautiful fluorite and fine quartz crystals. The former mineral
occurs intimately mixed with the limestone, and presents itself in the most beautiful green, purple
and pink colors. Upon several' specimens octahedral forms were observed, but not very distinct. It is
seldom that entire crystals can be procured, since blasting is invariably necessary to reach them; consequently fragments are the result. Quantitative analyses of the purple and green varieties were
made. Purple variety: Fl 49.20 per cent. Ca 50.87 Fe,O, .. . ...... trace 100.07 The mean of the
specific gravities of five specimens was 3.21; ranging from 3.17-3.24. The shade of purple varied very
much in the specimens examined. Green variety: Fl 49.0.0 per cent. Ca 50.91 Fe20, trace 99.91 Sp.
gr. about the same as in case of the purple. South of Emmaus in the Lehigh mountains Mr. Benj.
Sadtler, Jr., found this mineral in perfect octahedra of deep purple color in a granitic rock. (Smith,
1883, p. 272.) The rather widespread but sporadic occurrence of small particles of fluorite in both the pre-Cambrian and Paleozoic strata of the State brings up the question of its origin. Although at the
present time there seems to be a preference among geologists for the belief in magmatic waters as
the source, the writer strongly inclines to the belief that most, if not all, the occurrences of fluorite in
limestone known to him within the State have been formed by artesian waters of meteoric origin.”


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Green & Purple Fluorite, New Paris, PA Purple Fluorite, New Paris, PA
(Photos by Ken Casey 2007)

     This is most I have been able to find online to date, as to the specifics of Pennsylvania Fluorite
geology.  Since more would be beyond the scope of this article, I would suggest for any good
researcher to hit the stacks in college libraries for more.  I know I will.

     Likely, Mr. Miller’s observations are exciting as to occurrence; however, I would suggest his
theory upon its formation to be valid only in some instances.   Though, I would offer that the hydrothermal
process is more likely in most.

     Clear and colorless 1mm cubes from the Wheatley Mine, Phoenixville, PA, were analyzed at the
American Museum of Natural History in 1931. Quantitative results of this well-provenanced sample
suggest a pure calcium fluoride (Calcium, 50.81% and Fluorine, 48.29%).


     According to the USGS Commodity Inventory by State: Pennsylvania (January 3, 2000), Fluorine-
Fluorite’s value is nil.  Though it is not a mined stone, like the fluorspar in Tennessee,
collectors still find it valuable.


     Our club’s recent collecting experience has lead us into the purple fluorites of several Lancaster
County area active limestone quarries: Binkley-Ober, Kurtz, Prospect Aggregates, Burkholder, and
farther north and west, Meckley’s Quarry in Mandata, Northumberland County.

     Meckley’s fluorite crystals are usually subhedral or euhedral; whereas, the other four quarries
contain well-formed cubes, some gemmy in appearance.


Two Museums of Note

     New to our MOTM format is an offering to you of two museums of note.  Of course topical, I
suggest two museums to expand your tour: one local, and one with an internationally impressive
collection.  So, here's to the Iron Hill Museum in Newark, Delaware and the Carnegie Museum of
Natural History in Pittsburgh, Pennsylvania.  Cheers!     

     Our local museum is a friend to our club, The Iron Hill Museum.  Under the auspices of the
Delaware Academy of Science, Director Laura Lee was kind enough to loan briefly some massive
Fluorite specimens for a top-notch display case in our March 3-4, 2007 Show.     

     Our museum of world fame is the Carnegie Museum of Natural History.  With their $20,000.
acquisition of PA Fluorites, their Hillman Hall collection boasts superb old finds for us to view.     

     William W. Jefferis of West Chester, PA, sold his massive collection to the Carnegie Museum of
Natural History in 1904, which contained several fine Pennsylvania Fluorite specimens.   Jefferis was
a contemporary of James D. Dana, whose System of Mineralogy holds several specimen pictures
from Mr. Jefferis' collection. (Source: "History of Hillman Hall", Carnegie Museum of Natural History)     

     The "Masterpiece Gallery" has had several outstanding purple fluorite on white quartz specimens,
since 2003.     

     One can also find Fluorite prominently displayed in the collections of the Yale Peabody Museum
and the Irénée DuPont Mineral Museum at the University of Delaware.



     As we fellow MOTM-trekkers already know, we have visited Fluorite on two other occasion in:
January Mineral of the Month: Fluorite  June Mineral of the Month: Antarctic Fluorite, both in 2005.

     In these articles, we have covered fluorite's uses across the board.  As we are concentrating on
Pennsylvania Fluorite, I could say that the only two uses are: to enjoy as specimens, and to act as
an extremely minor constituent of rip-rap or cement.  That's what the quarries who encourage us to
visit with them do with their raw materials.  Thanks to all of the quarry owners and staff, who so
generously let us advance our interests in geology education!

     So, in the spirit of sharing uses, please enjoy this photo sampling from our club's past four years
of collecting:

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Massive Purple Fluorite in White Calcite,  Binkley-Ober


Massive Purple Fluorite in White Calcite,  Binkley-Ober
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Light, gemmy purple fluorites, Burkholder


Another Burkholder gem!
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Gemmy Binkley-Ober specimen (~1-2 mm cubes)


Joe Meloney's 2-foot x 1-foot fluorite plate from Kurtz!
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Fluorite hiding in calcite and quartz, Kurtz Large, broken fluorite crystals on pink dolomite, Binkley-Ober
(Photos by Ken Casey 2004-7)



Hillman Hall at the Carnegie Museum of Natural History

Penn State Earth & Mineral Sciences Museum and Art Gallery

Virtual Mineral Exhibit at the New York State Museum

Irénée DuPont Mineral Museum, University of Delaware

Peabody Museum of Natural History, Yale University


Members' Gallery

Here is where DMS Members can add their nice Fluorite photos to share with us.


Until Next Time

     We hope you have enjoyed our quaint visit to Pennsylvania Fluorite.  Please join
us next month, for another article, and we shall journey together!
     Until then, stay safe, and happy collecting. hardhat2a.gif (5709 bytes)



Article Contributors


Kerry Matt, Author and Central Pennsylvania Rock & Mineral Club Member

Benjamin Miller

Joe Meloney, DMS Member



Photo & Graphics Credits

I would like to gratefully acknowledge the generous contributions of our fellow PA Fluorite
enthusiasts, collectors, authors, curators, professionals, and club members who made this
work possible. 

Kerry Matt, Author and Central Pennsylvania Rock & Mineral Club Member

DCNR, Pennsylvania Geological Survey

Marchex, Inc., World Flag Database

©2007  All contributions to this article are covered under the copyright protection of this article
and by separate and several copyright protection(s), and are to be used for the sole purposes of
enjoying this scholarly article.  They are used gratefully with express written permission of the
authors, save for generally-accepted scholarly quotes, short in nature, deemed legal to reference
with the appropriate citation and credit.
  Reproduction of this article must be obtained by express
written permission of the author, Kenneth B. Casey, for his contributions, authoring, photos, and
graphics.  Use of all other credited materials requires permission of each contributor separately

Links and general contact information are included in the credits above, and throughout this article.
The advice offered herein are only suggestions; it is the reader's charge to use the information
contained herein responsibly.  DMS is not responsible for misuse or accidents caused from this
article. All opinions, theories, proofs, and views expressed within this article, and in others on this
website, do not necessarily reflect the views of the Delaware Mineralogical Society. 

Suggested Reading:



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   About the Author:  Ken is current webmaster of the Delaware Mineralogical Society.  He has a diploma in Jewelry Repair, Fabrication & Stonesetting from the Bowman Technical School, Lancaster, PA, and worked as jeweler.  He has also studied geology at the University of Delaware.  And, he is currently a member of the Delaware Mineralogical Society and the Franklin-Ogdensburg Mineralogical Society.  E-mail:

Invitation to Members


Want to see your name in print?  Want to co-author, contribute, or author a whole Mineral of the Month article?  Well, this the forum for you!

And Members, if you have pictures, or a story you would like to share, please feel free to offer.  We'd like to post them for our mutual enjoyment.   Of course, you get full photo and author credit, and a chance to reach other collectors, hobbyists, and scientists.  We only ask that you check your facts, give credit where it is due, keep it wholesome for our Junior Members watching, and keep on topic regarding rockhounding.

You don't even have to be experienced in making a webpage.  We can work together to publish your story.  A handwritten short story with a Polaroid will do.  If you do fancier, a text document with a digital photo will suit, as well.   Sharing is the groundwork from which we can get your story out there.

Our club's webpages can reach any person surfing the net in the world, and even on the International Space Station, if they have a mind to view our website!

We are hoping for a possible tie-in to other informative programs upon which our fellow members might want to collaborate.  Contact any officer or board member with your suggestions.

Our next MOTM will be a surprise.  For 2007, we are waiting for your suggestions.  What minerals do you want to know more about?

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Most of the Mineral of the Month selections have come from most recent club fieldtrips and March Show Themes, and from inspriring world locales. thus far.  If you have a suggestion for a future Mineral of the Month, please e-mail me at:, or tell me at our next meeting.



Past Minerals of the Month
January 2007 Mineral of the Month: Sillimanite
December 2006 Mineral of the Month: Hedenbergite by Karissa Hendershot
November 2006 Mineral of the Month: Brandywine Blue Gneiss
October 2006 Mineral of the Month: Spessartite by Karissa Hendershot
September 2006 Mineral of the Month: Native Silver
August 2006 Mineral of the Month: Kryptonite
July 2006 Mineral of the Month: Azurite
June 2006 Mineral of the Month: Pyromorphite
May 2006 Mineral of the Month: Tsavorite by Karissa Hendershot
April 2006 Mineral of the Month: Variscite
March 2006 Mineral of the Month: Petrified Wood, Part II
February 2006 Mineral of the Month: Petrified Wood, Part I
January 2006 Mineral of the Month: Strontianite by Karissa Hendershot
December Mineral of the Month: Clinozoisite
November Mineral of the Month: Bismuth
October Mineral of the Month: Wulfenite by Karissa Hendershot
September Mineral of the Month: Turquoise
August Mineral of the Month: Peridot
July Mineral of the Month: Ruby
June Mineral of the Month: Antarctic Fluorite
May Mineral of the Month: Dolomite, Part 2
April Mineral of the Month: Dolomite, Part 1
March Mineral of the Month: Calcite
February Mineral of the Month: Agate
January Mineral of the Month: Fluorite
December Mineral of the Month: Pyrite
November Mineral of the Month: Stilbite  
October Mineral of the Month: Celestite   

This page last updated:  February 19, 2011 10:14:43 AM




Next Meeting

April Program, Monday, April 8, 2013:

"Destruction of the Fossil Exposures in the Chesapeake Bay Area" presented by Dr. Lauck Ward

General Club Meeting:
April 8, 2013

We are meeting at
Greenbank Mill

Special Meetings:

*Show Committee Meeting, April or May, 2013

*New Home/Lapidary Committee, 2013

*Board Meeting,  April, 2013

Next Field Trips


Past Fieldtrips

Next Show
DMS March Show
March 1-2, 2014 at DelTech Stanton


Our 2013 Show Theme was:
"All That Glitters is as Good as Gold!"

March Show 2013 Report






Fossil Forum

"Dinny, the Dino"

"Belemnites are coming"


MOTM June also commemorates our 50th Show!

It's shiny, yellow, and is a symbol of 50 Years!Can you guess?


Collecting Adventure Stories:

"Sunny Brook Crick Goethite" by Joe Dunleavy