Introduction
Colors of Fluorite
Fluorite Coloration
Local Fluorite (Purple)
Exotic Locations
U. S. Occurrences
U. S. Commercial Fluorite Mining & Industrial Uses
World Famous Locales
Exotic Antarctic Fluorite
Fluorescence and Theories
Fluorite Paragenesis
Quarries in our area that have purple Fluorite (Slideshow)
Crystallography
Once You Have Them

(Top Right) Fluorite: Cornwall, England
Gemmy red octahedron from the Dick & Maria Nelson Collection

(Bottom Left) Fluorite on Dolomite: Tagebau, Caaschwiitz, Germany
A pair of gemmy, zoned fluorite cubes from this little known German locality. PrettyTN!  Photo courtesy of Isaias Casanova

(Bottom Right) Fluorite: Berbes, Spain
Transparent pink perfect gem for anyone's serious collection
Photo by Dick Nelson

Introduction

Actual Colors of Fluorite Cubes digitally sampled from Fluorite Photos

Colors of Fluorite

     Fluorite has the distinction of occurring naturally in many colors.  Predominant hues are green and purple.  It also occurs in a wide range of yellow to red-orange to brown.   Clear, colorless specimens rival those of the bright blues and pinks.  Our local quarries and those all over world are chock full of amazingly colored crystal clusters for your collection.

     Visibly, its crystal structure is easier to understand than most minerals, as it occurs mainly in its characteristic cubes or octahedrons.  Many-sided hedral shapes occur more rarely, as well as twins.   Sometimes color can be matched to a particular crystal form (paragenesis).

Fluorite Coloration

     What makes Fluorite so colorful?  Well, as pure Fluorite (or Calcium Fluoride, CaF₂) is colorless and clear, some mechanism must exist to pose visible color throughout its crystal matrix.  “Pure fluorite (CaF₂), made of the elements calcium (Ca) and fluorine (F), is colorless. The various colors result from tiny amounts of other elements substituting for the calcium in the crystalline structure.”[i] This is the simplest explanation.

     A more complex geochemistry has been debated over the last century: “The cause of color in fluorite has been studied and debated for almost 100 years.  Several enduring theories have arisen for some of the numerous colors in which fluorite occurs. These include electron transitions on structural defect centers, specifically Frenkel defects, impurity-associated defect centers (i.e. REE coordinated F centers), and impurity ions, such as divalent REE, themselves [1].”[ii]  Such rare and sometimes radioactive constituents are referred to as REE, or Rare Earth Elements.

     Quantitative analysis has shown that certain Pennsylvania purple fluorite consists of CaF₂ with iron oxide as a trace element:  Ca 50.87%, F 49.20%, and Fe2O3 (trace amounts), totaling 100.07%.”  A study of the green variety shares near identical results: Ca 50.91%, F 49.00%, and Fe₂O₃ (trace amounts), totaling 99.91%.[iii]   No radioactive components are shown present.

     Iron oxide is a known ‘chromophore’ or coloring agent in minerals.  Mostly transition metals on the Periodic Table of Elements comprise nature’s arsenal of coloring agents.  Ferrous iron (Fe²⁺) promotes green coloration.[iv]  “In some cases the color is attributable to appreciable amounts of an element, such as iron, that has a strong pigmenting power.”  Also, “[t]he ions of certain elements are strongly light-absorbing and their presence in small, even trace, amounts may cause the mineral to be deeply colored.  Chief among these elements known as chromophores are: Fe, Mn, Cu, Cr, Co, Ni, and V.” (p. 190)[v]

     Crystal structure is the real key to understanding this phenomenon.  Sometimes the radiation of RREs contribute to widen the range of coloration.[vi]   Most purple fluorite found on our fieldtrips in PA has been either massive or simply cubic.

    This author would argue that our local purple Fluorite consists of Calcium Fluoride with no rare earth element (REE) believed to act as either chromophore or ‘activator’ towards fluorescence, as upon ‘UV lamping’, the specimens did not fluoresce.  One test for “[p]urple fluorite found in association with radioactive minerals becomes colourless on heating above about 175°C [347°F]…”[vii]

     Though, purple fluorite can be an indicator of the presence of uranium[viii], this is not yet proved to the author’s satisfaction in quarries we visited in southeastern Pennsylvania.  And since, iron oxide is not known to activate fluorescence; therefore, with only visible color to contend with, the producing agent of its purple color is, most likely, iron oxide.  So, our search for the perfect purple fluorite crystal leads us to search for locations containing iron oxide.

 Local Fluorite

     The Fluorite that we know from nearby Pennsylvania is usually purple, based upon our experience.  Also small crystals of colorless, white, green, blue, or yellow have been found.[ix]   “Fluorite has been noted…in numerous places throughout the State [of Pennsylvania], especially in calcite or dolomite veins in the limestones.  Most of it is purple, but the light green variety has also been found.”[x]

Purple fluorite cubes on pink dolomite saddles, Kurtz Quarry (Photo by Ken Casey ©2004)

     In essence, the best places to look for good crystals are in Pennsylvania limestone quarries.  As it is known that the application of water to crystals can dull their luster, the freshest specimens, protected from the rain, are found in active quarries.  Also, we need to scour the map to locate typical assemblages of hydrothermal deposits.  These fluorite associations include: calcite, dolomite, pyrite, limonite (pseudomorphs after pyrite, or ‘iron oxide’), quartz, and sometimes barite and sphalerite.  These are places that we have visited on recent field trips.  

Past Field Trips

Exotic Locations

     We also find green fluorite in New Hampshire at the Wise Mine (NEFTA fieldtrips).  Specimens in all colors of the rainbow can be found as near as the Midwestern U. S., and as far as China.  In fact, this mineral can be found on all seven continents, even Antarctica![xi]  Bob’s Fluorite Gallery lists specimens and pictures from all six, but our southernmost landmass.

U. S. Occurrences

William Wise Mine, Westmoreland, New Hampshire (superb green octahedrons)
http://www.treasuremountainmining.com/tmmwisemine.html

Ballard Mine, Sweetwater, Tennessee and Elmwood, TN area (gray, green & purple cubes)
http://www.gamineral.org/ballard-mine.htm

Fluorite Mine, Cady Mountains (Afton Canyon area) located about 50 miles east of Barstow, California (green)
http://www.cfmsinc.org/Newsletter/News2004/007Jul04/newsjul04.htm

Purple Passion Mine, Wickenburg, Arizona
http://www.fluorescents.com/randg.htm

Monarch Mine, Wickenburg, AZ on BLM land (green & purple octahedrons up to 2 inches)
http://www.fluorescents.com/randg.htm

Bluffton Stone Company Quarry, Bluffton, Allen County, Ohio (purple, brown, pink, clear, white, yellow, gold, brown, brownish black) cubes or trisoctahedrons, with phantoms)
http://www.rockmanjoe.com/bluffton.htm

 To view a listing of world famous fluorite sites by color: http://www.fluorites.com/sites/sites.htm.

U. S. Commercial Fluorite Mining & Industrial Uses

     Fluorite ranks as an important commercial mineral.  It is used as flux in steel-making, glass-making, enameling, as well as uranium production and the manufacture of hydrofluoric acid (HF).  The Midwestern United States boasts viable deposits.  Four western states have also supported its extraction: Colorado, New Mexico, Montana, and Utah.   Today, very little, if any, U. S. fluorite mining is going on.  The last and largest domestic fluorspar mine closed in 1995, leaving tailings for future collection.   “The Kentucky-Illinois fluorspar area once was ranked first in the United States in the production of fluorite.”[xii]

           ©2005
Illinois State Geological Survey (ISGS) (Cave-in-Rock, Rosiclaire Maps)
Fluorite:  Minerva Mine # 1, Cave in Rock, Illinois (5.5x5x3 cm) Photo: Isaias Casanova
Bluish cubes of fluorite with rich purple zones and minor black spots of hydrocarbons.

    Important mines in Rosiclaire and Cave-in-Rock, Illinois were part of this famous mining district.  In fact, in 1965, the state’s General Assembly made Fluorite the official Illinois state mineral.[xiii]   Today, an historical marker stands near the famous Rosiclaire site, erected on June 3, 1995.[xiv]  For us collectors, we can note that some deep purple fluorite found here does fluoresce, and can still be collected.

World Famous Locales

     There are many famous collection locations for Fluorite around the world.  Most notable locales exist in the U. S., England, Spain, Italy, China, and France.  The original hotspot for collectable fluorites is in the United Kingdom.  In England, Cumberland, Derbyshire, Durham, and mines in Saxony have shown the most promising specimens.  For example, the Rogerley Mine in Weardale, England has historically supplied collectors for over 150 years.  Specimens from this locale are bright green and fluoresce blue in strong daylight.[xv]

    Whether you would just like to view and study these phenomenal collections, purchase them at a local rock, gem & mineral show, or plan a travel adventure for self-collecting, here are a few resources, organized by major locale:

     Spain boasts at least two major collection locales for purple: Asturias and La Vescias.
http://finequartz.com/cgi-bin/index.pl?str=Fluorite&ptr=0

    Italy offers superb violet cubes from Cagliari’s Is Murvonis Mine, and light green cubes hail from the Su Zulfuru Mine.
http://www.italianminerals.com/ITALY/fluorite.html

   China has light and deep green octahedrons, and colorless, and purple cubes from Hunan Province.
http://www.danweinrich.com/china-fluorite-2.htm

     France shares some hearty, pink octahedrons from the Argentiere Massif, Mount Blanc, Chamonix.
http://www.trinityminerals.com/sm2001/chamonix2.shtml

Exotic Antarctic Fluorite

     Surface deposits have even been explored.  “The sediments of the Tarn Flat [Antarctica] lake derive from local materials, modified in silicate fraction and enriched in calcite and fluorite.”[xvi]   Even the USGS lists Fluorite in its Commodity Inventory of Antarctica.[xvii]

     
Credits: (L. to R.): NSF, National Geographic Society, Lynn Teo Samarski (NSF), Ann Parks Hawthorne (NSF)

     “There has never been any commercial mining in Antarctica, there are no current plans to mine Antarctica and mining is currently completely banned by the Antarctic Treaty. There are no known future plans by any of the Antarctic Treaty nations to reverse this decision.”[xviii]

     So, collecting here is prohibited.  Some lucky few of us might join a geologic expedition in the future.  To our Junior Members (and the rest of us, young-at-heart), finding well-preserved fluorite crystals on Antarctica, may rival your desire to search for life on Mars.  If you wish, I hope you get to do both, one day. 

     For the future, you will need a map or guide.  Here is one theory of exploration that can lead you to at least geologically analogous sites on four nearby continents:

      One theory set forward by David Leach of the USGS uses the process of Continental Drift as proof.   In that Australia was once connected to Antarctica (as part of the ancient supercontinent, Pangea), geologies of the formerly joined landmasses must be similar.   And that, “The series of intense tectonic events associated with the assimilation of Pangea in Devonian to Permian time account for at least 71% of total MVT Pb-Zn metal that have been mined to date.”[xix]  Also, “These deposits account for the bulk of the world's resources for lead and zinc together with significant resources of Ag, Ge, Co, fluorite, and barite and Ni (the largest resource for Ni in the U.S. is in the old lead-belt MVT district of Missouri).”[xx]

     Therefore, if one finds fluorite at the connective boundary in Australia, another may find it at its corresponding boundary in Antarctica.  The same goes for the southern tip of South America, the African coast, and India, as well.

     Though, never mined, purple fluorite does exist there.  I would imagine that legally procuring a specimen or even a photo would be a grand achievement.  As the world is full of this spectacular mineral, one could spend decades combing our planet for specimens, and relegate oneself to dreaming of the day toward participating in a grand expedition to this frozen continent.

       Courtesy of the University of Texas

Fluorescence and Theories

     Neither the Early Roman metallurgists (BCE/AD), nor the Renaissance chemists of 1549 AD[xxi], knew to use fluorite’s fluorescent properties.  They only utilized its property of ‘ease of flow’ under heat, making the mineral perform as flux [Latin, fluere, to flow] in their metalwork.[xxii]

     The person credited with this discovery was the British scientist Sir George Gabriel Stokes.  In about 1851, he noted that certain English fluorites glowed bright blue in sunlight.   He coined the term ‘fluorescence’ after the mineral’s name in a paper of 1852.[xxiii]

     He published on “Stokes Law in 1852. Sometimes referred to as Stokes shift, the law holds that the wavelength of fluorescent light is always greater than the wavelength of the exciting light.”[xxiv]   Like Sir Isaac Newton, Stokes was an advocate of light study and optics.  He has laid some immense groundwork for our modern, mathematical understanding of our favorite fluorite.

     Now, how does this apply to our purple fluorite specimens?  Well, it is the play of color that excites most students, scientists, and hobbyists.  It seems as magic to illuminate a fluorite cube with an invisible beam of light and observe a bright emanation of ‘dayglow’ colors; especially, if the emanating color is different from the daylight color of one’s specimen.  Without its discovery, we would only marvel at the myriad hues we observe in daylight—if that is not enough!

     To proceed, let us properly define our application of fluorescence.  “Fluorescence in minerals is the result of bombarding the mineral with invisible ultra-violet light waves. This releases visible light waves (photons) of different wave lengths (colors) from the mineral.”[xxv]   There are two major delineations of UV light for our model: longwave and shortwave.   A collector can purchase, borrow, or share a dedicated UV lamp that may one or two outputs, covered by a purple glass, known as Wood’s glass.  Each output will produce either a longwave, or a shortwave light.  A mineral’s fluorescence may behave differently under each wavelength.

     Most simply, for our purposes, “[f]luorite fluoresces best under the long wave U. V. light. This usually produces a blue light. In our long wave case the green fluorite fluoresces blue.”[xxvi]

     “Many Fluorites fluoresce a blue-violet color due to traces of europium; this is usually best under longwave UV. Fluorite also fluoresces green, yellow, red, and white. Some will fluoresce one color under short-wave, a second color under longwave, and even a third phosphorescence. Other activators in Fluorite include Yttrium, Samarium, and some organic impurities.”[xxvii]  For example, “[f]luorite from Weardale fluoresces brightly purple while fluorite from Derbyshire rarely fluoresces.”[xxviii]

     “Certain electrons in the mineral absorb the energy from these sources and jump to a higher energy state. The fluorescent light is emitted when those electrons jump down to a lower energy state and emit a light of their own.”[xxix]   Sometimes the fluorite will glow for several seconds after the UV lamp is turned off.  This bonus light is termed ‘phosphorescence’.

     With this application we can further enjoy our perfect specimen!

Fluorite Paragenesis

     When fluorite is not the desired mineral to be mined in commercial quantities, even as a gangue mineral can be used as clue to the presence of desired metal sulfide ores.  “[G]angue and ore minerals in many instances are genetically related.”  For example, the presence of a dark purple fluorite may indicate the availability of uranium, lead, or zinc ore bodies nearby.”[xxx]

     Two Russian mineralogists, Ganzeyev and Sotskov, stated in a 1976 article on the composition of their native fluorites that: “Overall, the trace REE's encountered in the highest concentrations were ytterbium (Yb), cerium (Ce), samarium (Sm), and lanthanum (La), in that order. Also found in fluorite were europium, terbium, lutetium, and strontium (not a REE, but tested for anyway).”[xxxi]  And that “…the amounts of trace REE's corresponded with the conditions under which the fluorite crystallized.”[xxxii]  

Quarries in our area that have purple Fluorite

     As a matter of fact, we discovered a bonanza of such finds at our November 20, 2004 fieldtrip to Kurtz Quarry in Denver, PA.  Bob, Karissa, Joe, John, Tim, Guy and Wendy reaped the benefits of a basic geologic knowledge of the quarry.  Eric and Jake found the nicest pyrite/calcite vein I’ve seen in awhile!

Fluorite in calcite vein, Franklin, NJ (Photo by Ken Casey ©2004)

     Other Pennsylvania quarries offer similar possibilities.  In 2004, we have visited a few: the Kurtz Quarry in Denver, the Binkley-Ober Quarry in East Petersburg, PA, Meckley’s Quarry in Mandata, and a NEFTA trip to Doylestown, PA.   Known locations of others are: Oak Hall Quarry, College Township, PA and the Ormrod Quarries of Heidelberg Cement.  Our VP of Fieldtrips, Bob Asreen, is working to setup an excursion to Martin Limestone’s Burkholder Quarry in Lancaster County.  The Nittany Mineralogical Society has reported finds of “some handsome fluorites” there.  This is just in our own backyard!

Crystallography

     Fluorite shares a common, visible crystal structure with such minerals as Pyrite.  It crystallizes in the Isometric System and usually forms cubes, octahedrons (less likely), and rarely dodecahedrons (12-sided figures).  Often nature combines the forms into twinned, interpenetrating cubes, or cubes with their corners modified.  One could speculate that since iron pyrite (FeS₂) forms cubes like our predominantly purple fluorite (with trace amounts of iron oxide) that fluorite’s tendency toward forming cubes in our local area would be worthy of investigation.

For more on Fluorite, see: http://www.mindat.org/min-1576.html.

     On recent fieldtrips, we have found mainly purple cubes, measuring about 1-5 mm.  It is possible, that upon future adventures, we will come across larger, green cubes for sampling.

Once You Have Them

     One you have them, what next?  Well, there are many means of enjoying and sharing your most excellent specimen of fluorite.  The first thing is to prepare your crystals for viewing.  That is best done with a very soft-haired brush, as fluorite scratches easily (Moh’s Hardness Scale of 4).  Though insoluble in water at temperatures collectors use, brushing with water can dull the luster of the crystal faces, I’m told by fellow collectors.   Or, soak them in water and dish soap for a few days.[xxxiii]   The use of acids is ill advised.

     Next, it’s up to you.  You can display it at home, show it at our next club meeting, or junior members and teachers could show it as an educational tool.  Trading or selling your specimen is entirely up to you.  And, if you deem yourself generous enough to give it away or donate to a school or museum, you reap the intrinsic rewards of sharing.

     Some folks go one step further, and process their finds into stonework or jewelry, using lapidary techniques.  Being relatively soft, fluorite takes shaping and polishing easy enough.   Though somewhat fragile, it makes for brilliant cut stones, vases and vessels, spheres, and most popularly today, beads.

     Once you have collected the perfect specimen of fluorite, you may never go back to the ordinary, less colored and less-photoactive minerals.  Thanks for joining me on our adventure.  If you are in the neighborhood, drop by one of our meetings to discuss this article and more.  (We meet the second Monday of every month, except July and August.)  Until we can meet upon the frozen shores of Antarctica, Happy Rockhounding to you on every continent.

         
Antarctica Photo Credits (L. to R.):  Lynn Teo Samarski (NSF), Bert Rowell (NSF)

Links

Museums & Galleries

Smithsonian Institution’s Janet Annenberg Hooker Hall of Geology, Gems and Minerals Virtual Tour (Their site is under construction)

World Famous Locales

UK Mining Ventures, England

Webliography/ Bibliography

Illinois State Geological Survey “Geobit 4: Fluorite—Illinois’ State Mineral, November 7, 2003, ISGS. January 5, 2005
<http://www.isgs.uiuc.edu/servs/pubs/geobits-pub/geobit4/geobit4.htm>.

Wright, C. L., and Rakovan, J. “COLOR, ITS CAUSE, AND RELATION TO REE CHEMISTRY AND
PARAGENESIS OF FLUORITES FROM THE HANSONBURG MINING DISTRICT IN BINGHAM,
NM” Eleventh Annual V. M. Goldschmidt Conference (2001): 1 page. 3 Jan. 2005
<http://www.lpi.usra.edu/meetings/gold2001/pdf/3887.pdf>

Miller, Benjamin L. Lehigh County Pennsylvania Geology & Geography, Fourth Series Bulletin C39. Pennsylvania Department of Internal Affairs, Topographic and Geologic Survey: 1941. Lehigh  University Digital Library, PA. 2 Jan. 2005<http://digital.lib.lehigh.edu/qbuild/geo/viewer.html?CISOROOT=/geology&CISOPTR=576&
CISOROWS=2&CISOCOLS=5&CISORESTMP=/qbuild/geo/results.html&CISOVIEWTMP=
/qbuild/geo/viewFrame.html;title=LC>

Aber, Susan Ward “Course Lecture: GO 340 Gemstones & Gemology: Visual Properties”.
Emporia State University. 28 Dec. 2004. 30 Dec. 2004
<http://www.emporia.edu/earthsci/amber/go340/visual.htm>  

Hurlbut, Jr., Cornelius, and Klein, Cornelis, Manual of Mineralogy (after James D. Dana), 19th
edition, London: Longman Group Limited, 1976.

Bean, Rachel “Course Lab: Geology 202a: Mineralogy: Lab 3: Mineral Colors”. Bowdoin College.
Due: 4 Feb. 2003.  22 Dec. 2004
<http://academic.bowdoin.edu/courses/s03/geo202/dissemination/lab3color.pdf>

Deer, W. A., Howie, R. A., and Zussman, J. An Introduction to the Rock Forming Minerals.
London: Longman Group Limited, 1976.

Hagemann, Steffen “Geology 364: Ore Genesis Lecture Notes: Hydrothermal Alteration
Systematics”. 2001. 2 Jan. 2005
<http://www.virtualgeology.com/pages/teaching/364/lectures/alteration/>

Barnes, John H. Rocks and Minerals of Pennsylvania, Education Series 1, 4th series.
Harrisburg: Pennsylvania Geological Survey, 2004
<http://www.dcnr.state.pa.us/topogeo/education/rocksminerals/es1.pdf>

Read, Stephen E., Cooper, Alan F., and Walker, Nicholas W. “Geochemistry and U-Pb
geochronology of the Neoproterozoic-Cambrian Koettlitz Glacier Alkaline Province, Royal
Society Range, Transantarctic Mountains, Antarctica.” Geology Department, University
of Otago, New Zealand, Institute of Geological and Nuclear Sciences, Dunedin, New
Zealand. 20 Nov. 2002. 30 Dec. 2004
<http://www.otago.ac.nz/Geology/features/kgap/images/kgap2000.pdf>

“Rocks and Minerals of Kentucky: Fluorite”. Kentucky Geological Survey, University of
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“Fluorite Mining”. Illinois State Historical Society, Springfield, IL. 4 Jan. 2005
<http://www.historyillinois.org/frames/markers/92.htm>

Specimen #M255. Mt. Lily Gems, Burnsville, NC.
<http://www.mtlilygems.com/Minerals/M255.html>

BERTELLE, M., LEOTTA G., CALOGERO, S., Università di Venezia, Venezia, Italy;
ODDONE, M. Università di Pavia , Pavia, Italy “CHARACTERISATION OF SEDIMENTS
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by Continent 01/03/00 Antarctica (2)". U. S. Geological Survey, Reston, VA. 30 Dec. 2004
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Ward, Paul. “Cool Antarctica: Human Impacts on Antarctica and Threats to the Environment -
Mining and Oil”. 27 Dec. 2004. 30 Dec. 2004
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Leach, David. “Sediment-hosted base-metal deposits”. U. S. Geological Survey, USGS
Central Region Mineral Resources Team, Reston, VA. 24 Sep. 2003. 2 Jan. 2005
<http://minerals.cr.usgs.gov/projects/ore_forming_processes/task2.html>

Jolyon, Ralph. “Fluorite”. Mindat.org—The Mineral Database. Croydon, Surrey, London,
England, UK. 20 Dec. 2004
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<http://www.mineralminers.com/html/fluminfo.htm#backinfo>

Abramowitz, Mortimer (Oympus America, Inc.), Johnson, Ian D., Parry-Hill, Matthew J.,Flynn,
Brian O., and Davidson, Michael W. (National High Magnetic Field Laboratory, The Florida
State University, Tallahassee, FL). “Fluorescence”. Tallahasee: Molecular Expressions.
21 Sep. 2003. 2 Jan. 2005
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Cross, Bob. “Fluorescence in Minerals…”. San Jacinto College. 3 Jan. 2005
<http://www.ghgcorp.com/gpenning/ff11.htm> 

“Fluorescence in Minerals”. Minershop.com. 30 Dec. 2004
<http://www.minershop.com/html/fluorescense.html>

Macolm, Gavin. “Mineral Gallery: Fluorescence in Minerals”. UK: The Russell Society, 2003.
2 Jan. 2005
<http://www.russellsoc.org/fluointro.htm>

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<http://mineral.galleries.com/minerals/property/fluoresc.htm>

Thorsten, Christian. “CR-Scientific Minerals & Earth Science newsletter, HTML archive
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Rylands, C. J. P. “The Rock Candy Mine: Plates of Fluorite, Barite and Quartz!”. 1997.
4 Jan. 2005
<http://www.washington-state-rockhounding.info/rockcandy-collecting.htm#8>

Photo, Graphic & Literary Credits

Dick Nelson (c/o IC Minerals)
Isaias Casanova, IC Minerals
Eric Greene, Treasure Mountain Mining & eBay store
Chris Thorsten, CR Scientific and at Chris's Mineral Collecting Page
Karissa Hendershot, President, Delaware Mineralogical Society
The National Geographic Society, (through the NSF)
The National Science Foundation (NSF):
Lynn Teo Samarski, Ann Parks Hawthorne, Bert Rowell
Institute for Geophysics, University of Texas (Pangea)
Illinois State Geological Survey (ISGS) (Cave-in-Rock, Rosiclaire Maps)

© 2005  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.

End Notes

Past Minerals of the Month

December Mineral of the Month: Pyrite

Invitation to Members

All of the Mineral of the Month selections have come from most recent club fieldtrips, thus far.  If you have a suggestion for a future Mineral of the Month, please e-mail me at: kencasey98@yahoo.com, or tell me at our next meeting.