Some Minerals of the Buckwheat Dump,
Especially the Ore and Contact-Zone Rocks

By C. Thorsten


This list includes those minerals which occur in the ore tailings and / or the contact-zone or calc-silicate rocks which comprise the Buckwheat Dump at Franklin. NOTE: some of these minerals also occur in the "Buckwheat dolomite", which is listed separately.

Initially this list was supposed to be for micro-minerals, but it has come to include many of the macroscopic and fluorescent species that can be found at Buckwheat.  A few of the minerals from the Franklin Marble are also mentioned.

The "Frequency" ratings are for the overall species as found on the Buckwheat Dump.  Certain sub-varieties of a given mineral may be quite rare on the dumps.  For example, willemite on the dump is common, but blue willemite and "radiating" willemite are very rare.



ACTINOLITE: occurs as greenish, needle-like or bladed crystals. Found with franklinite, willemite, calcite, and what appears to be goethite. Also found in assemblages with microcline, quartz, and / or serpentine.  Moderately common, but distinct crystals are hard to find.  Even good micro xtl sprays are not all that common.
Frequency:  Common

ALLANITE: found as elongated, crude crystal shapes in microcline / quartz assemblages (the "pegmatites", which at Franklin often include andradite garnet and other "skarn" minerals). Can be weakly radioactive, but it's nothing compared to uraninite.  Look in the "dirty" (unattractive) microcline rocks, though it can occur in the amazonite.  Allanite appears as brown to black crystals, usually broken, in the feldspar or quartz.
Frequency:  Common

ANDRADITE is common in massive form on the dump, but once in a while you can find decent crystals of it which are a few millimeters across.  Occasionally, centimeter-sized crystals appear.
Once, I dug up a remnant of an andradite crystal that would have been four inches across.  It was badly dinged up and missing all its points, so I didn't keep it.
Frequency:  Common

ARSENIAN FLUORAPATITE:  See "FLUORAPATITE", below.

ARSENOPYRITE: occurs sometimes as silvery grains with pyrite and franklinite in the white calcite on the Buckwheat.  Also sometimes occurs in the Buckwheat dolomite.  It's uncommon. See also LOELLINGITE, below.  There are those who insist that all the silvery-colored metallic sulfides found on the Buckwheat are pyrrhotite;  this is incorrect.  Some of them clearly contain arsenic and are entirely non-magnetic even in powder form.
Frequency:  Uncommon

BARITE:  
"Hey, Freddy, check this out.  Purple fluorite!"  
"Oh yeah, cool."
"Want a piece?"
"Nah."
After I got a sample, we rolled the boulder down into the trench and forgot about it.  I took the piece home and, on a lark (there's never any good fluorescent minerals with purple fluorite, don't you know...), I checked it with the short-wave lamp and found it contained numerous grains of fluorescent barite
Frequency:  NF variety probably Common,  FL variety Rare to Very Rare

BASALT
is not a mineral, but a rock.  That is, basalt is an assemblage of minerals.  Technically the rock at Franklin is probably diabase, but the distinction is really only a matter of grain size.  Some of the Franklin material indeed rings like basalt when you hit it with a hammer, and it's very fine-grained.  Basalt (or diabase) is very common on the dump and usually devoid of any good minerals.  Once in a while you can find a ribbon of fluorescent ore running through basalt, or the other way around.  Such vein pieces are always desirable, but plain old basalt is not that great unless it's fashioned into an article such as a basalt bed, a basalt drinking glass, or a basalt car with square basalt wheels and a basalt engine block.
Frequency:  Very Common

BEMENTITE: a light tan, micaceous or foliated mineral, bementite is very unusual on the Buckwheat Dump but does occur there. In 1998 I found one piece about the size of a small potato.  John Cianciulli recognized it immediately when I showed him (at the time I had no idea what it was).  Bementite weathers on the outside to resemble just about every other rock on the dump, so don't ask me how I found it! 
Frequency:  Very Rare

BUSTAMITE is similar in composition and appearance to rhodonite, but it displays a more striated or fibrous habit on freshly fractured surfaces.  It occurs sometimes with hardystonite, franklinite, tephroite, glaucochroite, and / or andradite.  Fluorescent bustamite is quite rare on the dump.  It gives a deep red color in long-wave UV, though some specimens fluoresce in short wave.
Without consulting the literature, offhand I'd say bustamite and rhodonite probably form a solution series that makes them difficult to distinguish from one another.  I do know they can occur together in the same specimen, which complicates things.  "Pure" bustamite tends to have more of a silky appearance on fracture surfaces, but I've seen rhodonite that does this as well.  A lot of what's found is probably calcian rhodonite that doesn't have quite enough Ca to be called bustamite.  Both likely contain some zinc, as well.
Frequency:  Uncommon

BIOTITE (see also MANGANOPHYLLITE and HENDRICKSITE):  dark brown to black mica that occurs in the calcite associated with franklinite, willemite, and other minerals.  Fairly common on the dump.  When high in zinc and manganese, it becomes hendricksite.  Much of the ore-related black mica is probably hendricksite, while the material in the very sparse ore rocks and contact zone rocks is probably biotite.  To know for sure, though, you'd have to do some tests.  There is also black PHLOGOPITE, which can add to the confusion.
Frequency:  Common

CALCITE:  Can be white, gray, pink, orange, or dirty brown on the Buckwheat Dump.  Much, if not most of it, fluoresces a bright red-orange in short-wave UV.  Some of it fluoresces a beautiful bluish in mid-wave (MW) and long-wave (LW) UV, vaguely similar to the Terlingua-type calcites but not as intense.
Frequency:  Very Common

CERUSSITE:  Despite the fact that the Dunn monograph (1995) says this mineral does not occur on the Buckwheat, I have found definite crystals of it there.  Then again, I've spent more time on the Buckwheat than anyone in recent years, with the possible exception of Fred and Kurt.  To be fair, one has to realize that a massive work such as the Franklin-Sterling Hill monograph would not leave its author much time to spend collecting minerals on the dump.  There is much down on that rock pile that has so far escaped study.  We have to be careful saying "mineral XYZ does not occur";  a more scientifically-accurate statement would be "no verified specimens of mineral XYZ are yet known by this author."  Even the most learned author may simply not be aware that someone has already found a specimen of that mineral and had it analyzed (or done sufficient analysis to verify it reasonably). 
It is common sense that where there is weathered galena, there is going to be cerussite (and possibly anglesite).  I still have the specimen in case there are any doubters.
Frequency:  Rare to Very Rare

CHALCOPYRITE: not all of the golden- or bronze-colored metallic minerals you'll find on the Buckwheat are pyrite. Chalcopyrite does occur in small specimens, though it's much less common. The crystal form is different from that of pyrite.  Because of its copper content, chalcopyrite assumes the "peacock ore" surface coloration more readily than does pyrite.
Frequency:  Uncommon

CHLOROPHOENICITE { (Mn,Mg)3Zn2(AsO4)(OH,O)6 } has indeed been found on the Buckwheat Dump.  It occurs as whitish, acicular crystals that line vugs and cavities in Franklin ore.  Any whitish, acicular crystals that are not willemite and which occur in the ore have a good chance of being chlorophoenicite (or perhaps brandtite).
Frequency:  Rare

CLINOHEDRITE occurs as veins, coatings, spots, or fracture fillings in specimens of hardystonite.   Very rarely it is found without hardystonite present, since it is generally an alteration product of hardystonite.  Fluoresces tangerine-orange in SW UV.
Frequency:  Rare

CUSPIDINE:  Several specimens have now been found on the Buckwheat.  The first one I know of personally was my find in the 1980's, though someone else undoubtedly ran into it before that.  I have found at least one good cuspidine specimen on the Buckwheat since, along with a few having sparse coverage. 
The fluorescent color is somewhere between yellow and orange.  In mid-wave UV (MW), cuspidine fluoresces a lilac color.
Frequency:  Very Rare

A specimen found recently

Left:  found recently at the Buckwheat.  The yellow-orange fluorescing material is the cuspidine.  Of course, there's a possibility it's johnbaumite, but so far the other collectors to whom I've shown it have said cuspidine.  The presence of glaucochroite (visible in daylight) supports this.

Note the spots of hardystonite in the calcite.  The ubiquitous willemite is also present.

Field of view is about 2 1/2 inches wide.


DIOPSIDE:  the variety "ZINC-SCHEFFERITE" is a platy, dark green or caramel-brown form that occurs in the calc-silicate rocks on the dump. Microcline, quartz, and / or hyalophane often accompany the green form.  The "zinc-schefferite" varieties do not fluoresce.  They usually don't occur in good crystals but are interesting to look at.  The caramel-brown material is very uncommon on the dump, while the green stuff is easier to find.
Diopside is a clinopyroxene.  Most of it found in or near the orebody is probably a zinc- and manganese-rich variety that also probably grades into zinc- and manganese-rich varieties of aegirine and augite.  Confusing!
Diopside found in the marble rocks on the dump is generally white or colorless in normal light;  it often fluoresces blue-white in short-wave.  It is easy to miss in daylight, since it blends in so well with the surrounding marble.
Frequency:  Common

EPIDOTE:  found in the microcline assemblages and sometimes as veins in the diabase or basalt rocks ("camptonite"), though usually only in the coarser-grained material.  The massive form is common, but well-formed crystals are always worth saving.
Frequency:  Common

ESPERITE was the stuff of legend for a while.  I have found rocks that by all accounts should have had esperite in them, based on the "look" they had in daylight, but they were devoid of the prized mineral.  I had, however, heard second-hand tales of its being found on the Buckwheat.  Some of these tales turned out to be mistaken I.D.;  norbergite and powellite both fluoresce yellow, for example.  Finally, one day, I saw a photo of a specimen Scott Allen had found.  It was a genuine, no-mistaking-it specimen of esperite.  He found it on the Buckwheat.  This would have to be the first definite Buckwheat esperite I've ever seen, although if the tales are to be believed, it has come off the dump several times in the past decade.  

FLINKITE { Mn2+2Mn3+(AsO4)(OH)4 } should be present on the dump; I believe it has been found there in the past.  It forms tiny aggregates of honey-brown to greenish-brown crystals and is sometimes associated with jarosewichite and cahnite.  As expected, these minerals occur in or near the ore, rather than the pegmatites or the dolomite.

FLUORAPATITE: found as blue-green prismatic crystals in bustamite or hyalophane. Usually the crystals are broken, since they are quite brittle. Sometimes you'll find an intact one or two, and they can be several millimeters long. Some are "bent", probably due to plastic deformation of the rock deep in the earth.
     Fluorapatite is also found as gray, blue-gray, tan, or pinkish regions in andradite-franklinite-willemite matrix.  This mineral often fluoresces orange under SW UV.  It is most likely an arsenian variety that is not far in composition from johnbaumite, turneaureite, etc.
Frequency:  Uncommon; good fluorescent specimens are rare.

FLUORITE  (CaF2):  The sherry-colored "chlorophane" occurs in black ore rocks, sometimes with fluorapatite and usually with a dull-fluorescing willemite. 
Purple fluorite sometimes occurs in the white calcite rocks, but it's a lot harder to find than the sherry-colored material. 
Frequency:  Common, but good, rich specimens are uncommon to rare

FRANKLINITE: the material from the Buckwheat dump appears as grains and crystals which are generally much smaller than those at Sterling Hill.  Near-perfect octahedrons of franklinite can be found in the Buckwheat calcite, measuring about 0.5 mm to 1 mm across. The only reliable way to expose such tiny crystals, however, is with acid etching (acetic or dilute hydrochloric).  Either that or else you must be very skillful with a needle to scrape away the calcite!
Frequency:  Very Common, but sharp, ideal crystals are rare outside the micro realm

GAHNITE:  usually found as massive, crumbly, dark green to almost black misshapen crystals, with calcite and rhodonite.  Occasionally, sharp crystals have turned up.  I'm told that some of those "black ore" rocks that contain willemite & sphalerite actually have a matrix of massive gahnite, not franklinite.  The two minerals are both in the spinel group and both contain zinc;  I'd imagine they could grade into one another chemically.
Frequency:  Uncommon

GALENA: found as small, shiny-faced cleavage masses. Fairly unusual at Franklin. I have found galena only 3 or 4 times on the Buckwheat, usually in very small amounts.  There was one 2 1/2" chunk I recovered that was almost solid galena.  When I tried to trim it, the specimen broke into three pieces.
Small spots of galena do sometimes occur in the andradite-microcline-quartz assemblage that's home to the  pink-fluorescing meionite.
Frequency:  Rare

Galena from Franklin, NJ
Left:  galena specimen found on the Buckwheat recently.  The bronze-yellow mineral in the rock is probably pyrite. Galena is actually rare at Franklin.

Be sure to wash the hands after touching lead minerals such as galena.   Do not panic, though;  consider, first of all, that galena is highly insoluble in water.  It is also quite rare at Franklin.  Chances are that you will not find this mineral there unless you're purposely seeking it.

GLAUCOCHROITE:  Many times the sight-ID experts rely on assemblages, but some experts are not familiar with dump-collected rocks (instead focusing on what I call "Harvard Museum assemblages" - beautiful but cherry-picked specimens that don't represent most of what came up from the mines). 
The pinkish or purplish-raspberry-pink material that occurs in the cuspidine assemblage is almost certainly glaucochroite.  There is also glaucochroite in a dump-collected assemblage containing bustamite, andradite, hardystonite, franklinite, and willemite.  Some of this glaucochroite exhibits the characteristic color-change behavior:  pinkish under incandescent light, bluish-gray in white fluorescent light.   LEUCOPHOENICITE has a similar appearance without the color-change behavior;  this also came from the Buckwheat Pit.
Frequency: Uncommon

GROUTITE occurs as metallic, black or silvery-gray micro crystals (acicular, usually) in or on the typical Franklin ore rocks.   This is probably the safest bet for an I.D. on any acicular, metallic Mn oxide mineral found at Buckwheat.
Frequency:  Rare

HARDYSTONITE
is found as gray or tan, glassy or dull masses, usually in calcite.  It is associated with franklinite, andradite, willemite, tephroite, and / or bustamite.  Hardystonite fluoresces a beautiful blue-violet color in SW UV.  It's hard to find on the Buckwheat, but once in a while a really nice one surfaces.   Small specimens consisting of tiny spots in calcite can usually be found after any given day of thorough searching.
The most unusual hardystonite I've ever found was pink in daylight and strongly resembled bustamite.
Frequency:  Rare

HEMATITE:  While common elsewhere in the world, a good find of crystalline hematite on the Buckwheat is noteworthy event.  A good specimen of metallic black hematite with radiating habit was found on the dump in 2000.  The black hematite had dull red hematite on and around it.  I have another, very similar specimen I bought from the descendent of a Franklin miner.  The assemblage contains andradite and a mixture of gray and pink, manganoan calcite-dolomite that fluoresces weakly.
Frequency:  Common, but good specimens are rare

HENDRICKSITE:  This appears in my 2004 copy of Fleischer's Glossary as a valid species.  It is similar to biotite but contains zinc and usually some manganese.  Most of the purplish-black mica that occurs in the ore rocks is probably hendricksite.
Frequency:  Common

HUMITE group:  includes CHONDRODITE and NORBERGITE;  found in the marble with diopside, tremolite, graphite, and sometimes sulfide minerals (pyrrhotite, etc).  May or may not fluoresce a yellowish color in SW UV.  Most of the stuff on the dumps doesn't fluoresce that well, though I'm assuming it's because the good ones were carted off in previous years when people used to be able to drive into the dump with their cars and fill up the trunk with Buckwheat rock. 
Frequency:  Common

HYALOPHANE is a barium feldspar that occurs with microcline, garnet, and other associations. It can fluoresce a deep magenta color SW.  While it is not uncommon in massive form on the dump, well-formed crystals seem to be very rare.
Frequency:   Common

"JEFFERSONITE" is a local name for one or more of the pyroxenes (mostly augite), especially when found in weathered form.  It is common at Sterling Hill but does also occur on the Buckwheat Dump at Franklin.   The material usually called "jeffersonite" has a characteristic appearance:  crude, opaque, elongated or stubby crystals with a dull, sooty brown or black surface.   Jeffersonite is often home to interesting secondary minerals that can be seen with a loupe or microscope.
Frequency:  Uncommon

JOHNBAUMITE is an apatite-group mineral that occurs in the ore rocks.  It can be confused with the equally-rare cuspidine, since it fluoresces a similar color in SW.  There are some differences in their mid-range response.  Something that responds yellow-orange in short-wave and lilac to pale violet in mid-wave is probably cuspidine rather than johnbaumite.
Frequency:  Very Rare

LOELLINGITE: or perhaps arsenopyrite. One or both of these silvery-white metallic minerals can be found sometimes on the Buckwheat. Crystals were well-known in the Franklin deposit, so you might find a really good micro specimen or two if you comb the dump. I have one piece of "rotten" or weathered dolomite which contains either loellingite or arsenopyrite. Two tests for these minerals are (1) tiny particles are nonmagnetic, distinguishing them from pyrrhotite, and (2) freshly broken samples give off the garlic-like odor of arsenic.
The tin-white, metallic mineral that occurs in the so-called "black ore" rock (the same kind of rock that's often host to "cleiophane") is most likely loellingite.
Frequency:  Rare

MAGNETITE is easy enough to distinguish from FRANKLINITE by using a magnet, although the latter mineral is sometimes weakly magnetic.  Actually, franklinite and magnetite can occur as exsolution lamellae within the same crystal, so a specimen could quite literally be both franklinite and magnetite at the same time.  And hematite, too.
Frequency:  Uncommon

MALACHITE or some other greenish, secondary copper mineral occurs in very small amounts as micro-spherules or coatings in ore rocks on the Buckwheat. Sometimes it is found with a blue-tarnished, metallic mineral that may be bornite or chalcopyrite.  In November 2005 I found a piece of microcline that contained epidote, galena, and what appeared to be malachite.
Frequency:  Rare

MANGANAXINITE is another mineral for which I keep searching but have not found any verified specimens from the Buckwheat.  However, in 2005 we did find a piece of non-fluorescent, massive material that very strongly resembled manganaxinite.  It had "that look" that experienced collectors often associate with Parker / Palmer material.  Even though rock from that operation was not dumped on the Buckwheat, there have been a few vaguely "Parker"-type rocks found on the dump here.
If you are lucky enough to find a red-fluorescing mineral that resembles manganaxinite, the easiest way to make sure it isn't calcite is to treat it with dilute hydrochloric acid.  Bubbles indicate calcite.  The "brief intense phosphorescence" (BIP) test can also be useful.
Frequency:  Very Rare, if it in fact occurs here

MANGANITE
:  Dunn (1995) says this is very rare at Franklin.  One day on the Buckwheat I was taking apart a recalcitrant "pyroxenoid" boulder.  There was a weathered portion that contained some "jeffersonite".  In a small cavity were black, metallic, acicular crystals of what I assumed were manganite.  However, they could just as easily be GROUTITE or HAUSMANNITE.  I still have that specimen around somewhere, I hope.  The crystals didn't resemble anything I had found on Buckwheat before or since.  Aside from the characteristically Franklin matrix in which they were situated, the crystals reminded me more of something from the Harz Mountains of Germany.
Frequency:  Very Rare, whatever it is.  

MANGANOPHYLLITE:  This is not an official IMA name as far as I know.  It refers to a manganese-rich variety of biotite.  If there is also zinc, as there probably is in any mica associated with Franklin ores, it would be HENDRICKSITE rather than manganophyllite.  Hendricksite is an accepted, separate species from biotite. 

MEIONITE (SCAPOLITE):  I'm operating under the assumption that marialite (the other scapolite-group member) is rare at Franklin, a fact Dr. Dunn and others have told me on several occasions. 
The most interesting meionite on the Buckwheat occurs in a certain kind of contact-zone rock near the boundary between quartz / feldspar "pegmatite" on the one side and andradite-rich skarn on the other.  This material is rare but fluoresces an eerily beautiful lilac color in short-wave UV.  I spent several weeks' worth of Buckwheat trips looking only for this kind of meionite, and I didn't find all that much of it.  A fairly powerful SW lamp is necessary to see the color well.
Meionite overall is reasonably common on the dump, but most of it doesn't fluoresce very well.  Good crystals seem to be very rare on the Buckwheat.
Frequency:  Common, but good fluorescent specimens are Rare

MICROCLINE:  The dirty, gray-green material is quite common on the dumps.  The pleasantly-colored variety known as AMAZONITE is somewhat harder to find.  Some Franklin microcline fluoresces a pale powder-blue or blue-white in SW UV, like a much paler version of margarosanite.
Frequency:  Very Common; good fluorescent specimens and rich green daylight material are uncommon

MOLYBDENITE: small, steel-gray or silvery flakes, easily mistaken for graphite
Frequency:  unknown, because it's so easily confused with graphite

MUSCOVITE: a light-green variety (unusual!) occurs in the contact-zone rocks with quartz and feldspar. This type of muscovite looks just like margarite, and to tell the truth, I can't distinguish between the two right now.
Frequency:  Uncommon

NORBERGITE is primarily a marble mineral, occurring as pale yellow-fluorescing grains, sometimes with blue-white FL diopside.  It does not occur in the ore rocks, although the late Nick Zipco once had for sale a specimen that had norbergite but looked as though it could have come from the edges of the orebody.  It was really odd, and I've never seen another like it.

PARGASITE
is not normally an orebody mineral.  It occurs in the marble boulders as light green to grayish grains or crystals, although some of these may be EDENITE.  These are both amphiboles, so they will have the same general appearance and crystal form.  Visually distinguishing them can be difficult or impossible.
Some pargasite does fluoresce, although I haven't spent enough time in search of this particular mineral to know if specimens from the Buckwheat do so.

PETEDUNNITE:  A zinc pyroxene, petedunnite is not really that exciting to look at (though it has its own beauty when polished).  It is either dark, dull green or a lighter, olive-drab color.  The lighter material is an impure form of petedunnite that usually contains willemite.  This willemite occurs here as spots that fluoresce in short-wave UV to give the impression of glowing green cauliflower.  The petedunnite assemblage also contains GENTHELVITE, but this is rare and usually occurs only in specks.
Frequency:  Uncommon

PHLOGOPITE is commonly found as light brown flakes in calcite or marble assemblages on the dump.  Some of it fluoresces a dull yellow in SW UV.  Now and then you can find intact crystals of phlogopite.  By the way, this mineral can contain significant amounts of Fe / Mn / Zn, have dark or almost black coloration, and still be phlogopite.  As a general rule, if you're at Franklin and near the ore, it's probably Hendricksite.  In the pits at Sterling Hill, or in Franklin rocks away from the ore, a mica could be phlogopite or BIOTITE.
Frequency:  Common

POWELLITE occurs as small, isolated specks of dull whitish-yellow to canary-yellow fluorescing material, sometimes associated with molybdenite. Powellite is very uncommon at the Buckwheat, but we've found some by digging. You probably will not find crystallized specimens of it, however, though there could be pseudomorphs after molybdenite.
Frequency:  Rare

PYRRHOTITE is a dull, bronze-yellow color with metallic or submetallic luster;  it looks like pyrite or tarnished arsenopyrite. Pyrrhotite crushed into small particles will stick to a magnet.  It also has a lower hardness than arsenopyrite.  Pyrrhotite forms crystals with a hexagonal cross-section, though I've never found any crystals at Franklin.  The massive form is pretty easy to find in the dolomite.
Frequency:  Common

QUARTZ is uncommon outside the dolomite.  It does not occur directly in the ore rocks, but it is found in the contact-zone rocks.  Sometimes there is significant willemite in the quartz, giving the whole assemblage a unique appearance in SW UV. 

RHODONITE
can be pink, dull brown, or even gray.  It doesn't withstand weathering very well and can lose its pink color in a matter of a few days' exposure to weathering.  The best rhodonite on the dumps is a pale powder-pink color, but you can find it only by breaking open a rock.  It will always weather to black on the outside;  in fact, just a few hours' exposure to the elements can cause the color intensity to fade.
There's a material we call "dead rhodonite" which doesn't have much associated with it that fluoresces, doesn't have good daylight color, and is generally one of the hardest rocks to break-- even harder than basalt.
Frequency:  Common

SCHEELITE occurs almost exclusively in "black ore" rocks, sometimes with sphalerite and fluorapatite.  Typically there is some black willemite.  Franklin scheelite fluoresces white with a hint of yellow, suggesting molybdenum content.  Good, rich specimens worthy of display are quite rare.  Almost every specimen I've ever seen has consisted of only isolated specks of scheelite.
Frequency:  Rare

SONOLITE looks like a "pink tephroite" and is chemically similar to that mineral, though it also contains fluorine and hydroxyl ions. Sonolite would be found with zincite and franklinite, as well as tephroite.  Most of the would-be sonolite I've found has turned out to be glauchochroite or pink tephroite.   Since sonolite contains F and the other two do not, I can think of at least one test (capillary tube test with heat + KHSO4) that should distinguish them.
Frequency:  unknown, probably rare.

SPHALERITE:  The best sphalerite on the dump occurs as veins of silvery-looking material running through white calcite.  This fluoresces a beautiful orange color in SW and usually LW and MW UV as well.  Some of it is also blue in LW and/or MW UV;  this is the variety known locally as "cleiophane".  The brown and oil-green varieties of sphalerite do not normally fluoresce.
Frequency:  Common, but good fluorescent ones are Rare

STILPNOMELANE is in the same group as lennilenapeite and franklinphilite (both of which occur on the Buckwheat). I think Dunn's monograph (1995) says most of the "stilpnomelane" at Franklin is in fact lennilenapeite or franklinphilite.  "Stilpnomelane"-like minerals may occur here as golden-brown, foliated masses which coat fracture seams in the pegmatites and the contact zone rock (the quartz / feldspar / garnet assemblages).  It is not what I'd call common, but a determined search should yield at least a micro specimen or two on any given day.
Frequency:  Uncommon

TEPHROITE is a manganese silicate and can be gray, blue-gray, greenish, brownish, or even pinkish. It is similar in molecular structure to willemite, though tephroite contains manganese in place of zinc and also does not fluoresce.  This seems counter-intuitive, because it is actually manganese, not zinc, that causes the fluorescence of willemite.  Tephroite does form crystals (though they're uncommon) and does occur on the Buckwheat Dump.  I've found small, somewhat misshapen crystals in orebody-calcite rocks;  at first glance these crystals appeared to be brown, tan, gray, or even dull pink willemite... until examined with the UV lamp, where they gave no response.
Frequency:  Common

THORITE {(Th,U)SiO4 } occurs in small grains, usually altered.  This dull or burnt-orange variant is sometimes called "ORANGITE".   I found one or two pieces that were sight-ID'ed by John Cianciulli, and they gave a few counts per second above background;  others have found more significant specimens, but they're all pretty much in the realm of microminerals.
Frequency:  Rare

THORTVEITITE has been found recently on the Buckwheat, according to a collector of rare-earth / radioactive minerals who collects there sometimes.
Frequency:  Unknown but probably very rare

TURNEAUREITE is very rare on the dumps.  It occurs with andradite and calcite, generally the salmon-colored variety.  Turneaureite has been found on the Buckwheat on a few occasions.  It fluoresces a yellow-orange that's similar to other apatite-group and related minerals (johnbaumite, fluorapatite, cuspidine, etc).
Frequency:  Very Rare

URANINITE, when found, is usually in massive form, but sometimes there are small, cubic crystals of it.  As minerals go, uraninite is strongly radioactive. It is hard to find on the Buckwheat, but several collectors have found it there.  Even though Franklin was a zinc mine, not a uranium mine, there are going to be small amounts of uranium and thorium minerals almost anywhere there are pegmatites. 
Frequency:  Very Rare

WILLEMITE is a zinc silicate, almost always with traces of manganese. Quite a bit of willemite made it onto the Buckwheat Dump, even though willemite was one of the primary zinc ores and usually ended up in the crushers.
Tiny crystals can be found in calcite, some of which are transparent greenish. Of course, they fluoresce green under SW UV. Willemite can form acicular crystals. Probably 99% of the willemite crystals you find will be subhedral (rough / slightly misformed) or completely nondescript in shape (anhedral).  "Radiating" willemite, so named because of its distinctive crystal habit (reminiscent of wavellite), forms in the ore contact zone with dolomite.  It is extremely rare on the dump but has been found at least twice in recent years. 
There are probably 289 different colloquial names for the different varieties of willemite.  "Radiating" willemite refers to the radial habit of the crystals.  Miners used to call this "white willemite", but now "white willemite" refers to a variety of willemite that is simply white.  For some reason, this variety tends ot phosphoresce quite strongly.
"Black willemite" is black in daylight but fluoresces a subdued green in SW UV.
        "Blue willemite" is extremely rare.  Even blue-gray willemite is rare.  I've never found any of this.  Well, come to think of it, I've probably found some vaguely bluish-gray willemite, but not the really blue stuff.
  "Grape" willemite is purple, like grape juice.  This is a very popular variety of willemite and seems to be quite sought-after.  The phenomenon of a purple mineral fluorescing bright green presents a sort of dissonance that still makes me do a double-take. 
        "Orangeade" willemite was a kind that I found on the Trotter once.  It occurs with what looks like glaucochroite or perhaps grossular.  I found some on the Buckwheat, as well, though I don't remember if I kept any (if not, should have).
"Troostite" is a varietal name for an opaque, red-brown willemite that looks a bit like raw beef or perhaps Chuck Wagon brand dog food.  It is, in fact, sometimes called "beefsteak willemite".   Even after many years, "troostite" is still one of my favorites from the Franklin-Sterling Hill complex.  This probably has to do with the fact that it was one of my first "silver pick" acquisitions as a boy.  Or, maybe because it's just so representative of the locality.
        "Yellow willemite" is basically just willemite that's yellow.
        "Machine oil" willemite has the color of fresh machine oil:  sort of a dull, honey-brown color with a greenish cast.  It can be translucent.
There was a willemite specimen that had an appearance somewhere between "machine oil" willemite and "beefsteak" willemite.  One of my collecting buddies, who now wishes to be anonymous (wuss!) therefore coined the term "machine steak" willemite.  This was sort of an inside joke for a while.  It still gives me a laugh sometimes.  Anyway, the mineral willemite occurs in so many varieties that you could spend a lifetime trying to acquire them all (I won't even try).  Lawson Bauer, chemist for NJ Zinc Co., was said to have a box of specimens he used to show to visitors.  These specimens included rocks of practically every color, texture, and habit.  When the guests were unable to identify most of them, Bauer then revealed they were all willemite.  That's easy enough to do, of course, because the short-wave UV lamp makes them fluoresce green. 
Frequency:  Common

ZINCITE:  Crystals are very rare.  Large crystals are extremely rare.  Usually this mineral occurs in massive form.  It's not common on the Buckwheat.  Most of the decent specimens I've found have been very small, perhaps the size of a golf ball, and always mixed in with willemite and franklinite.  The prettiest zincite assemblage from Buckwheat has the mineral with grains of very dense, shiny franklinite and massive green willemite.  This is found, almost invariably, in small pieces only.  That's not suprising, given that most of this ended up going to the smelter.
Frequency:  Uncommon





Back to top


Back to main page