[Rockhounds] fulgurites

[Rik Dillen]

If anyone is interested : Prof René Van Tassel (does "vantasselite", an aluminium phosphate mineral, ring a bell ?), who
is still an active member of our mineral club, wrote an article on fulgurites for our magazine Geonieuws in 1999. He
described e.g. a fulgurite that was completely dug out in the Belgian locality Zutendaal, with a length of 8.4 m. This
fulgurite is now kept in the Belgian Museum of Natural History in Brussels. Het made at that time a list of the most
spectacular recovered fulgurites he could trace with certainty :

Table : recovered fulgurites with a length of 3.4 m and more.

1	Forster Pit, S.-Carolina, USA	J.J. Petty, 1936	60 ft	18 m
2	Rome, New York, USA	C. West, 1843	50 ft	15 m
3	Hergenrath II, Eupen, België	J.H. Willems, 1961		13 m
4	Drigg, Cumberland, UK	E.L. Irton, 1814	30 ft	9 m
5	S.-Carolina, USA	J.J. Petty, 1936	20-30 ft	6-9 m
6	Zutendaal, Limburg, België	R. Van Tassel, 1958		8.4 m (*)
7	Zonhoven II, Limburg, België	R. Van Tassel, 1955		7.5 m (*)
8	Hergenrath II, Eupen, België	J.H. Willems, 1964		7 m
9	Ludlington, Michigan, USA	G. Monk, 1941		7 m
10	Macclesfield, UK	Sainter, 1865		6.5 m
11	Massel, Schleswig, Duitsland	L.D. Hermann, 1711	20 Fusz	5.7 m
12	Neu-Moresnet, Eupen, België	P.C.R. Rademakers, 1963		5.8 m
13	New Jersey, USA	W.L. Barrows, 1910	19 ft	5.8 m
14	Zonhoven I, Limburg, België	R. Van Tassel, 1955		5 m
15	Westerhaar, Overijsel, Nederland	H. Krul, 1954		5 m (**)
16	Bantelge, Münster, Duitsland	K.G. Fiedler, 1817	15 par. Fusz	4.9 m
17	Starke, Florida, USA	F.W. Wright Jr., 1999	16 ft	4.9 m
18	Dresden, Saksen, Duitsland	K.G. Fiedler, 1822	8 L. el 53/4 Zoll	4.8 m
19	Dresden, Saksen, Duitsland	K.G. Fiedler, 1851		4.8 m (*)(***)
20	Guteborn, Saksen, Duitsland	W. Fisher, 1926		4.6 m
21	Sennerheide, Paderborn, Duitsland	O. Suffert, 1951 ; H. Krul, 1954		4.6 m (*)
22	Stanton Co., Nebraska, USA	E.H. Barbour, 1925	10-15 ft	3 - 4.5 m
23	Bantelge, Münster, Duitsland	K.G. Fiedler, 1817	13 par. Fusz	4.3 m
24	Starke, Florida, USA	F.W. Wright Jr., 1999	14 ft	4.3 m
25	Sennerheide, Paderborn, Duitsland	O. Suffert, 1951 ; H. Krul, 1954		4.3 m (*)
26	Hulshorst, Veluwe, Gelderland, NL	N. Tinbergen, 1942		3.5 m (*)
27	Massel, Schleswig, Duitsland	L.D. Hermann, 1711	6 Sachs. El 	3.4 m

And here is his literature list (mostly in Dutch, German and French) :

BECKERS H.J. (1955), "Bliksembuizen", Grondboor en hamer, 65-67.
DARTEVELLE E. (1942), "Les fulgurites", Ciel et Terre, 180-187.
DARTEVELLE E. (1945), "Fulgurites de Belgique", Bull. soc. belge Géol., 54, 254-257.
GAINES R.V., SKINNER H.C.W., FOORD E.E., MASON B. en ROSENZWEIG A. (1997), "Dana's New Mineralogy", Wiley, 8th edition.
HACQAERT A., (1939), "Een fulguriet uit de Limburgse Kempen", Natuurw. Tijdschr., 21, 3-6.
HARTING M.P. (1874), "Notice sur un cas de formation de fulgurites et sur la présence d'autres fulgurites dans le sol de
la Néerlande", Natuurk. Verh. kon. Acad., 14, 22 blz.
KRUL H. (1954), "Blitzröhrenfunde in Holland", Der Aufschluss, 5(6), 113-115.
LACROIX A. (1915), "La silice fondue considérée comme minéral (lechateliérite)", Bull. soc. franç. Mineral., 38,
182-186.
LACROIX A. (1915), "Sur les fulgurites exclusivement silicieuses du Sahara oriental et sur quelques fulgurites
silicatées des Pyrénées", Bull. soc. franç. Miner., 38, 188-198.
PITTOORS P. (1968) "Bliksembuizen. Heemkundig handboekje voor de Antwerpse randgemeenten", 16(1), 15-21.
PORADA G.M. en WITTIG R. (1975), "Geologische Wirkung von Blizeinschlägen", Natur und Mus., 105(8), 229-244.
RADEMAKERS P.C.M. (1963), "De bliksembuis van de Käskorb", Sprekende Bodem, 7(5), 46-50.
RODING G.M. (> 1959), "Verglaasde bliksem", De levende natuur, 67-71.
RODING G.M. en ZANDSTRA J.G. (1955), "Fossiele bliksems", Grondboor en Hamer, 43-48.
TINBERGEN N. (1942), "Een bliksembuis", De levende natuur, 47, 87-92.
VAN TASSEL R. (1955), "Fulgurites in situ à Zonhoven (Limbourg belge)", Meded. kon. Belg.Inst. Natuurw., 34(9), 24 blz.
VAN TASSEL R. (1958), "Une fulgurite ramifiée de Zutendaal, Limbourg belge", Meded. kon. Belg. Inst. Natuurw., 34(7), 8
blz.
WILLEMS J.H. (1961), "Een fulguriet te Hergenrath (provincie Luik, België)", Grondboor en Hamer, 322-332.
WILLEMS J.H. (1962), "Een opmerkelijk fulgurietfragment", Jaarb. Nederl. geol. Verenig., 14-16.
WILLEMS J.H. (1962), "Een fulguriet te Beek (Limburg)", Grondboor en Hamer, 133-137.
WILLEMS J.H. (1964), "De 'fulguriet II' van Hergenrath", Sprekende bodem 8(6), 92-93.
WEIGHT F.W., Jr. (1999), "Florida's fantastic fulgurite find", Rocks and Minerals 74(3), 156-159.


Rik DILLEN 
Doornstraat 15,  B-9170 Sint-Gillis-Waas 
Belgium 
E-mail rik.dillen at skynet.be 
Homepage : http://users.skynet.be/rik.dillen 
 

-----Original Message-----
From: rockhounds-bounces at lists.drizzle.com [mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of pmodreski at aol.com
Sent: Tuesday, September 16, 2008 7:17 PM
To: rockhounds at lists.drizzle.com
Subject: Re: [Rockhounds] fulgurites

It's been interesting to read everyone's comments about fulgurites; I've just been catching up on my Rockhounds email,
after being very tied up with the Denver Show, a preceding mineralogical conference in Golden, and having been away
visiting my family in New Hampshire the week before that.

You bet, lechatlierite is for sure a mineraloid.? The name is "traditionally" mentioned in mineralogy books, but it
definitely is not found in sources such as the Glossary of Mineral Species, which only list bona fide approved mineral
species.? Lechatlierite occurs in fulgurites, and has also been recognized in some impact-deformed rocks, subject to
intense pressure and temperature.? A somewhat analogous term is maskelynite, which is glassy (melted) plagioclase
feldspar from shock impact, known from some meteorites and (according to Mindat.org) from at least one terrestrial
impact structure.? I don't know if there is another such name, for melted potassium feldspar.

I've been interested to read people's comments about searching for, and finding, fulgurites.? I've always considered
that they are quite uncommon and very hard to find, and, like meteorites, I think almost all have been found by
accident, not by anyone's systematic searching.? (That statement used to be true for meteorites but no longer really as,
in view of the large number that have been found in Antarctica, as well as in the Sahara.)

Something that I have puzzled over, is, what proportion of lightning strikes, actually produce fulgurites?? I'm not sure
that anyone really knows this; there are thousands of lightning strikes every day, worldwide; but I'm not sure if anyone
knows if it does or doesn't take special conditions of soil/sand type, moisture, etc., to make a fulgurite.? It's likely
that in many instances, the lightning discharge may travel first through other material (such as trees and tree roots)
down into the ground before it begins to melt sand and form a fulgurite, so many fulgurite may be "hidden" underground,
and would not be found or noticed unless someone excavated in the right spot where there had been a lightning strike.

Likewise a puzzle--and we have talked about this before on this List--is how common it is for lightning strikes on rock
outcrops, to produce a fulgurite.? One always reads "anecdotally" that there exist melted patches on rocks near mountain
summits where lightning has struck, but I am still not sure that I have ever actually seen a picture of such a thing
(much less see one in person), or read any definitive documentation that ANYWAY has ever really seen such a thing.? My
suspicious is that most lightning strikes on mountains, if they do not hit trees, go to the crevices between rocks where
moist soil is likely to be more conductive, and that any melted rock that forms, may be in the form of rock fragments
contained in the soil down beside or in cracks within bedrock.? The closest I've seen is one specimen, in Kreigh's
collection, of a small piece of granite "from the Colorado mountains" partially melted by lightning; but I don't believe
the source of his specimen had provid!
 ed any specific information of how/what/where this actually occurred.? A few years ago, some collectors brought a large
fulgurite specimen to the Denver Museum of Nature & Science, from a lightning strike on a ridge high above Boulder
Canyon, in Colorado (the Museum subsequently acquired the specimen); it was from a lightning strike I believe at a tree
stump, and the fulgurite was excavated by digging out the crevices between and beneath the rocks around it; I don't
think any actual melted rock was observed on exposed rock surfaces.

Pete Modreski

-----Original Message-----
From: kugeln at peoplepc.com
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors <rockhounds at lists.drizzle.com>
Sent: Mon, 15 Sep 2008 6:17 pm
Subject: Re: [Rockhounds] fulgurites


Fulgurites are one of the very few mineraloids that are a true glass. The glass is known as LeChatelierite. Pete
Modreski, correct me if I'm wrong.?