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Vlasovite

Posted by Rock Currier  
avatar Vlasovite
November 10, 2008 08:52PM
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Vlasovite
Na2ZrSi4O11 monoclinic & triclinic
Canada
Quebec, Temiscamingue, Villedieu Township, Sheffield Lake, Kipawa Complex.
Vlasovite, Eudialyte 2cm high© 2001 John H. Betts
Vlasovite in Eudialyte 3.5cm tall © 2001 John H. Betts

Vlasovite is a rare fluorescent mineral which makes it of interest to collectors. The largest specimens contain crystals (lenses of pure material) up to 15 cm but fractured and cracked. These crystals are found in a matrix of potash feldspar and eudialite. In large crystals vlasovite is pale brown, but the smaller crystals always appear silvery owing to internal reflection from the excellent {010} cleavage planes.1They came from a place called the vlasovite pit which was collected by the Canadian National Museum. Another pit was called the eudialyte pit and here the best specimens rich in eudialyte associated with vlasovite eyes, rimed with gittinsite which is the type locality for that mineral. The largest “eyes” measure up to about 2x3 inches but are more commonly about a half inch in diameter. It fluoresces a butter yellow under short-wave ultraviolet light. The pit is about 10x30 feet and about eight feet deep. The material appears to have been worked out. The material is a honey yellow color. About 400 lbs. of specimens (about 40 flats) were collected by Derryl MacFarlane . In the Kola peninsula it occurs only as tiny grains of material.2

The mineral was found in surface workings. Discovered in 1955 by a Canadian government airborne radiometric survey. It was originally thought to be a uranium deposit but it turned out to be only rich in thorium. Unical company, a subsidiary of US Moly Corp, the company that mines Mountain Pass, California was interested in it for the zirconium and yttrium. It turned out not to be rich enough to make a mine. They cleared out about five acres on the shore of the lake for a camp. They used a skidder to clear an approximate 3 km strip along the outcrop of the complex and striped down to bedrock every 250 meters and washed the surface clean. Sampling and drilling indicated it was not worthwhile to mine, but they spent about a million dollars on development. This gave them the mineral rights for 65 years. There were over fifty claims on the complex. Derryl MacFarlane got involved in working the deposit for specimens in 1991 and concentrated in working a rich eudialyte pegmatite in the complex. The associated minerals are eudialyte, agrellite, vlasovite, gittinsite, mosandrite (rinkite”), calcite richterite, white feldspar, fluorite, thorite, and galena. The only access to the deposit is by boat or helicopter.1 The type locality is the Lovozero alkalic massif, Kola Peninsula, Russia where it occurs as irregular grains up to about 15 mm in diameter.
1. Canadian Mineralogist, Vol.12, P.211 The Occurrence of Vlasovite in Canada, J. Gittins, Elvira L. Gasparrini & S. G. Fleet.
2. Personal communication Darryl MacFarlane ~2005.
[Rock Currier 10 November 2008]



Click here to view Best Minerals V and here for Best Minerals A to Z and here for Fast Navigation of completed Best Minerals articles.



Edited 13 time(s). Last edit at 07/26/2010 11:56AM by Rock Currier.
avatar Re: Vlasovite
November 10, 2008 11:31PM
    
I'd spent some days on Vavnbed Mt. in NE Lovozero (the type locality of vlasovite), but hadn't found this point of mineralization. :( It is lost now.

On Kukisvumchorr Mt. in Khibina vlasovite was discovered by A.P. Khomyakov in drill-cores. According to him, vlasovite form here water-clear colourless to pearly (due to its perfect cleavage) monograins up to 2 cm and their agregates up to 3x5 cm. I am have 8x4 mm grain of vlasovite from the locality - it associate here with carrot-orange Zr-rich narsarsukite.

Dear Rock, Kola peninsula, not Lola. ;)
avatar Re: Vlasovite
November 11, 2008 12:02PM
Pavel,
Thanks for the information, Ill try and work it into the article on Vlasovite. When you get a chance, read what "we" have written about aluminum and let me know if its OK.

Rock Currier
Crystals not pistols.
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