Saturday, March 15, 2008
Is it a candy? no way Jose, it's a Wulfenite
Yeah, in fact it really looks like a candy, doesn't it? But not so fast my friends, Wulfenite (PbMoO4) may be subject to penalty due to the stiff Clean Air Act mandates, and regulations one of these fine days, as it contains lead and Molybdenum, both chemical elements hazardous to human beings. If you don't believe me, just check on the number of recalls to Chinese-made toys brought back to China, because of their lead content. God help us.
At any rate, secondary mineral Wulfenite is another interesting specimen, found in oxidation and enrichment zones with high saturation of lixiviated chemical elements from their original ore deposit, just like adamite, legrandite, hemimorphite, and goethite.
Wulfenite is abundant in Mexico (Chihuahua and Sonora), and in other areas of the world, such as the state of Arizona, in the USA, and the land of the dioptase: Tsumeb, in Namibia, Africa. Most beautiful crystals come from all these places, just like a contest, you never know which is producing a better looking one for the delight of the most avid mineralogist including yours truly.
Ok, how about if you take a look at the various features of Wulfenite including its name origin as follows:
Chemical Formula: PbMoO4
Molecular Weight = 367.14 gm
Environment: Secondary lead mineral. Forms a series with stolzite.
Locality: Bleiberg, Villach, Kärnten (Carinthia), Austria; Los Lamentos Mine in Municipio of Ahumada, Chihuahua Mexico; also in the San Francisco Mine, near Cucurpe in Sonora, Mexico, and so on.
Name Origin: Named after the Austrian mineralogist, Frantz Xaver von Wulfen (1728-1805).
Crystal System: Tetragonal - Dipyramidal
Cleavage:  Imperfect
Color: Orange yellow, Waxy yellow, Yellowish gray, Olive green, Brown.
Density: 6.5 - 7, Average = 6.75
Diaphaniety: Subtransparent to subtranslucent
Fracture: Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habit: Massive - Granular - Common texture observed in granite and other igneous rock.
Habit: Tabular - Form dimensions are thin in one direction.
Hardness: 3 - Calcite
Luster: Resinous - Greasy
Streak: Yellowish white
It's weekend time, I am in Anaco, and it's time to go to have dinner in Venezuela, and I think that maybe a couple or arepas, or cachapas with parchita juice will make it. Bon apetite amigos, have a terrific weekend.
Oscar el Mexicano