Wulfenite
Lead molybdate (PbMoO4)
A lead molybdate mineral famous for thin, brilliant orange to yellow tabular crystals, prized by collectors and an ore of molybdenum.
- Mohs hardness
- 2.5-3
- Color
- yellow, orange, orange-red, honey-brown
- Type
- mineral
Got a rock like this?
Identify any rock from a photo, free.
Overview
Wulfenite is a lead molybdate mineral (PbMoO4) renowned for its thin, square, tabular crystals in glowing shades of orange, yellow, and red. It is one of the most popular and photogenic collector minerals.
It crystallizes in the tetragonal system, often forming platy, almost paper-thin crystals with a brilliant resinous to adamantine luster. Color ranges from honey-yellow to fiery orange-red depending on trace impurities.
Named after the Austrian mineralogist Franz Xaver von Wulfen, it is also a minor ore of molybdenum and forms in the same oxidized lead deposits as vanadinite.
Formation & geology
Wulfenite is a secondary mineral that forms in the oxidized zones of lead and molybdenum ore deposits. It develops when primary lead sulfides such as galena weather and react with molybdenum-bearing solutions, typically in arid to semiarid environments.
It commonly occurs alongside vanadinite, mimetite, cerussite, and other oxidation-zone minerals.
World-famous localities include the Red Cloud Mine in Arizona (celebrated for deep red crystals), the Glove Mine and Rowley Mine in Arizona, Los Lamentos in Mexico, Mezica in Slovenia, and various sites in Morocco, Iran, and Namibia.
How to identify it
Look for thin, square, tabular crystals in vivid orange, yellow, or red, with a bright resinous to adamantine luster, often perched on matrix. The platy habit is very characteristic.
Wulfenite is soft (2.5-3) and heavy because of its lead content. The streak is white to pale yellowish.
Look-alikes include vanadinite (hexagonal crystals) and crocoite (elongate, brighter orange-red needles). The thin square tablets, glowing color, high density, and occurrence in oxidized lead deposits are diagnostic of wulfenite.
Uses & significance
Wulfenite is a minor ore of molybdenum, a metal used in high-strength steel alloys, and it has been a source of lead. However, most molybdenum comes from molybdenite, so wulfenite's industrial role is limited.
Its main value is to collectors, who prize its brilliant tabular crystals; superb red specimens from the Red Cloud Mine in Arizona are among the most coveted and valuable mineral specimens in the world.
Because it contains lead, it is not used in jewelry and should be handled with care, washing hands afterward. It has a small metaphysical following, but those claims are not scientific.
Frequently asked questions
What is wulfenite used for?
It is a minor ore of molybdenum and lead, but it is most valued as a collector mineral for its brilliant tabular crystals.
Why is wulfenite so popular with collectors?
Its thin, square, glowing orange-to-red crystals with high luster are striking and photogenic, especially specimens from Arizona's Red Cloud Mine.
Is wulfenite toxic?
It contains lead, so avoid inhaling dust, do not ingest it, and wash your hands after handling; displayed specimens are safe.
How do I tell wulfenite from vanadinite?
Wulfenite forms thin square tabular crystals, while vanadinite forms hexagonal prisms; both are heavy and brightly colored.
Where are the best wulfenite crystals found?
Arizona (notably the Red Cloud Mine), Mexico, Slovenia, Morocco, and Iran are famous sources.
Wulfenite guides
In-depth guides for identifying, valuing, and understanding Wulfenite.
