Scheikundige formule: Zn2SiO4
Familie: Silicaten
Status: IMA-GP
Kristal Systeem: Hexagonal
Mineraal om tentoon te stellen: Ja
Fluorescerende variëteiten: troostite, beta-willemite,UV Type | Kleur | Intensiteit | Frequentie van de observatie |
---|---|---|---|
Lange Golven (365nm): | Groen | Middelmatig | Zelden | Midden Golven (320 nm): | Groen | Sterk | Korte Golven(254 nm): | Groen | Zeer sterk | Soms |
Daglicht foto
WILLEMITE, Franklin, New Jersey, USA;
Photo and Copyright: James Hamblen
Site of the author
Used with permission of the author
Korte golf foto (254nm)
WILLEMITE under UVSW, Franklin, New Jersey, USA;
Photo and Copyright: James Hamblen
Site of the author
Used with permission of the author
Foto galerij:
...Naar de volledige galerij (14 beelden in totaal)
UV Type | Kleur | Intensity | Observation Frequency |
---|---|---|---|
Lange golven(365nm): | Groen | Sterk | Soms | Korte golven (254 nm): | Groen | Zeer sterk | Soms |
Thermoluminescencie: Ja
Willemite was first recognized in New Jersey in 1822, although it had evidently been mined there for many years before. It was then known as silicious oxide of zinc. The name willemite was applied by A. Lévy in 1880 to what afterwards proved to be the same mineral. His material was found in the Netherlands, and was named after Willem I (William I )(1772-1844), King of the Netherlands. It came from the small (less than 1,400 acres) neutral state of Moresnet situated between Prussia and Belgium (though the present kingdom of Belgium was not founded until that year--1830). Under the Treaty of Versailles (1919) it is now in Belgium. In this connexion it is interesting to recall that the name belgite has been suggested for this mineral. R. Panebianco, writing in esperanto in 1916, objected to naming minerals after kings, preferring a name derived from the locality. He, however, overlooked the fact that the locality was not, at that time, in Belgium ! From: South African occurrences of willemite. Fluorescence of willemite and some other zinc minerals in ultra-violet rays. By L. J. Spencer, Keeper of Minerals in the British Museum (Natural History). 1927 The occurrenee of willemite at Broken Hill, Northern Rhodesia was first recorded by Prof. H. Buttgenbach in 1919 (H. Buttgenbach. La calamine des ossements fossiles de Broken-Hill, (Rhodésie). Ann. Soc. Géol. Relgique, 1919 vol. 42) Troostite : willémite containing manganese ; Prior to the development of halophosphor in 1942, the first generation of phosphor used in fluorescent tube was synthetic willemite activated with manganese-II.
Beta-willemite nom erroné appliqué a une variété trouvée à Franklin-Sterling Hill et fluorescente en jaune ;
Certains échantillons de Brandtite fluorescents en vert OC devraient leur fluorescence à la willemite associée ;
Voornaamste Activator: Mn2+
Pieks in het spectrum (nm):
Mn2+ replacing Zn2+ : broad band peaking at +/- 525nm
Spectrum: Michael Gaft, Petah Tikva, Israel. Plot: Institute of Mineralogy, University of Vienna, Austria, with permission of the authors.
Lifetime: 400μs @520nm The action of ultra-violet rays on a large series of minerals of all kinds was tested by G. F. Kunz and C. Baskerville in 1903, and by E. Engelhardt in 1912. T. Liebisch in 1912 determined spectroscopically the nature of the green fluorescence from willemite. W.S. Andrews has pointed out in 1922 that artificially prepared willemite is only active when it contains some manganese, the shade of the green fluorescence depending on the amount of manganese present. Palache (1928) confirmed that the willemite containing manganese fluoresces the strongest. Dake (1941) stated that most connoisseurs of fluorescent minerals agree that willemite from Franklin an Ogdensburg, N.J. is the most spectacular of all luminescent minerals.
(*)Gegevens zijn niet exhaustieve, ze zijn beperkt tot de meest belangrijke plaatsen voor fluorescentie
Images:
http://www.mindat.org/show.php?name=Willemite
http://webmineral.com/data/Willemite.shtml
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