Franz Xaver von Wulfen - o jesuíta que era botânico, físico, matemático, alpinista e mineralogista - nasceu há 296 anos

   

Franz Xaver von Wulfen (Belgrado, 5 de novembro de 1728 - Klagenfurt, 16 de março de 1805) foi um padre jesuíta, botânico, físico, matemático, alpinista e mineralogista alemão. É-lhe creditada a descoberta das plantas Wulfenia carinthiaca, Saxifraga moschata e Stellaria bulbosa. Em 1845, o mineral wulfenite, de molibdato de chumbo, foi nomeado em sua homenagem por Wilhelm Karl von Haidinger.

  

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Wulfenite specimen from the Mina Ojuela, Mapimi, Durango, Mexico

   

Wulfenite is a lead molybdate mineral with the formula PbMoO₄. It can be most often found as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore".

It crystallizes in the tetragonal system, often occurring as stubby, pyramidal or tabular crystals. It also occurs as earthy, granular masses. It is found in many localities, associated with lead ores as a secondary mineral associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum, and is sought by collectors.

Wulfenite was first described in 1845 for an occurrence in Bad Bleiberg, Carinthia, Austria. It was named for Franz Xavier von Wulfen (1728–1805), an Austrian mineralogist.

It occurs as a secondary mineral in oxidized hydrothermal lead deposits. It occurs with cerussite, anglesite, smithsonite, hemimorphite, vanadinite, pyromorphite, mimetite, descloizite, plattnerite and various iron and manganese oxides.

A noted locality for wulfenite is the Red Cloud Mine in Arizona. Crystals are deep red in color and usually very well formed. The Los Lamentos locality in Mexico produced very thick tabular orange crystals.

   

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