The mineral Wulfenit is lead molybdenum (Pb(Mo04)). According to its symmetric elements and crystal shape, which reflect a crystal structure, it belongs to the tetra logical pyramid type of symmetry.

It was first mentioned as a "yellow lead ore" by Ljubljana's Jesuit professor Franz Xaver von Wulfen in 1785. The mineralogist Heidinger named the ore after Wulfen in 1845 calling it Wulfenit.

In the Mezica valley wulfenit appeared in the cracks of the limestone and dolomitic of middle Triassic age together with galena, phalerite and calcite in the highest and oxidized parts of the lead-zinc mine. Mostly square lamellate crystals were found measuring up to 7 cm. More rare were the pointed crystals, which measured up to 3 cm, with developed flat pyramids and dipyramids. Different shades of orange, yellow, red-orange, yellow-brown and brown colours reflect traces of different amounts of primary matter from the oxidized ore.
In three hundred years of mining in the area of Mezice more than 19 million tons of lead-zinc ore have been mined. Wulfenit as a molybdenum ore was interesting during the second World War when almost two thousand tons of concentrate with 20 per cent molybdenum in it was mined.
The Mezice crystals wulfenit, a threatened part of Slovenia's natural resources, are particularly valued in mineral collections due to their rarity, bright colours and interesting combination of crystal surfaces.

You can see Wulfenit Stamps also on FDC, MC and envelopes:
FDC of Slovenian Wulfenit Stamps,
envelopes of Slovenian Wulfenit Stamps,
MC of Slovenian Wulfenit Stamps,
FDC of Yugoslav Wulfenit Stamps.

And finally for dessert, my favourite commemorative evelopes of CINNABAR.
Slovenian Stamp of topic
Minerals - Fossils, Cinnabar is issued on March, 23th 1999.

Copyright 1997 JOE'S STAMPS . All rights reserved.
Revised: april 12, 2000