Wulfenite
Current inventory:  1 gem
 

  
Wulfenite is named after the Austrian mineralogist, Franz Xaver von Wulfen (1728-1805) who wrote a lengthy monograph on the lead ores of Carinthia in 1785.

Discovered in 1845;   IMA status:  Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

PbMoO₄

Lead Molybdate

Molecular Weight:

367.14 gm

Composition:

Molybdenum

26.13 %

Mo

39.21 %

MoO₃

Lead

56.44 %

Pb

65.15 %

PbO₂

Oxygen

17.43 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Sulfates

Strunz 8th Ed. ID:

6/G.01-30

Nickel-Strunz 10th Ed. ID:

7.GA.05

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
G : Molybdates, Wolframates and Niobates
A : Without additional anions or H₂O

Related to:

Scheelite Group. Stolzite-Wulfenite Series.

Members of Group:

Scheelite Group: Powellite, Raspite, Scheelite, Stolzite, Wulfenite

Varieties:

Calcian Wulfenite, Chillagite, Chromian Wulfenite, Tungstenoan Wulfenite, Vanadian Wulfenite

Synonyms:

Carinthite, Lead molybdate, Molybdate of Lead, Molybdenated Lead Ore, Yellow Lead Ore, Yellow Leadspar

Crystal Data

Crystallography:

Tetragonal - Dipyramidal

Crystal Habit:

Crystals commonly square, flat tabular on [001], showing {001} and flat or rounded vicinal faces, {010}, to 11 cm; may be elongated along [001], or pyramidal {011}. Commonly other {0kl}, {hkl} forms, some showing pyramidal hemihedrism; granular, massive.

Twinning:

On {001}, as contact twins, common.

Physical Properties

Cleavage:

Distinct on {011}, indistinct on {001}, {013}

Fracture:

Sub-Conchoidal to Irregular/Uneven

Tenacity:

Brittle

Moh's Hardness:

2.5 - 3.0

Density:

6.50 - 7.00 (g/cm³)

Luminescence:

Fluorescent; yellow to orange to red under SW UV and LW UV

Radioactivity:

Not Radioactive

Other:

Some individual crystals may be Piezoelectric.

Optical Properties

Color:

Yellow, pale Yellow, Yellow-Orange, Orange, Red-Orange, Gray, rarely White, Colorless, Olive-Green, pale to dark Blue, Reddish Brown, Brown, Black.

Transparency:

Transparent, Translucent, Opaque

Luster:

Resinous, Subadamantine to Adamantine

Refractive Index:

2.304 - 2.402  Uniaxial ( - ); may be anomalously Biaxial

Birefringence:

0.980

Dispersion:

Strong; (0.203)

Pleochroism:

Weak; orange and yellow

Occurances

Geological Setting:

A secondary mineral formed in the oxidezed zone of hydrothermal lead deposites, the molybdenum is commonly introduced externally.

Common Associations:

Cerussite, Anglesite, Smithsonite, Hemimorphite, Vanadinite, Pyromorphite, Mimetite, Descloizite, Plattnerite, Fe–Mn oxides.

Common Impurities:

W, Ca, V, As, Cr, W, Ti

Type Locality:

Bad Bleiberg, Bleiberg District, Gailtaler Alpen & Karnische Alpen Mts, Carinthia, Austria

Year Discovered:

1845

View mineral photos:

Wulfenite Mineral Photos and Locations

More Information

Mindat.org  
Webmineral.com

Wulfenite is a rare secondary mineral and very beautiful gem. It is rare because crystals are usually small, tabular and thin. Beautifully colored gems have been faceted from intense orange and reddish orange crystals found at the Red Cloud Mine (and others) in Arizona. Some large, pale yellow gems have been faceted from crystals found at Tsumeb, Namibia. There are many other sources of the beautiful crystal specimens worldwide including Los Lomentos, Mexico; Poland; Yugoslavia; Austria, Czech Republic; Germany Morocco and Australia. A few of these locations have also produced faceted gems.

There are hundreds of localities for Wulfenite; a few for fine examples include: from Bleiberg, Carinthia, Austria. At Mežica (Mies) and Crna pri Prevaljah (Schwartzenbach), Slovenia. In the USA, from Arizona, at the Red Cloud and nearby mines, Silver district, La Paz County, in the Old Yuma mine, near Tucson, Pima County, at the Mammoth-St. Anthony mine, Tiger, Pinal County, large crystals from the Glove mine, near Amado, Tyndall district, Santa Cruz County, at the Hilltop mine, Chiricahua Mountains, and in the Defiance mine, Gleeson, Cochise County; in New Mexico, at the Stevenson-Bennett mine, Organ Mountains, Doña Ana County; in the Lucin District, Elko County, Nevada. In Mexico, from the San Francisco mine, Cerro Prieta, Magdalena, Sonora; at Los Lamentos and Santa Eulalia, Chihuahua; in the Ojuela mine, Mapimí, Durango. Large crystals at Tsumeb, Namibia. Ponderous crystals from Mfouati, Congo Republic. In the Tchah Kharboze mine, Anarak district, Iran. At the Touissit mine, near Oujda, Morocco. From Sidjak, Uzbekistan. At the Christmas mine, Chillago, Queensland, Australia.
 

  
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