U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2009–3106

February 2010

USGS Mineral Resources Program

Molybdenum—A Key Component of Metal Alloys

Where Does Molybdenum Come From?

Molybdenum naturally occurs in a number of different forms, and the circumstances that 

control how, when, and where it is concentrated in the Earth’s crust are highly variable. Molybdenum 

is produced from both primary ore and as a byproduct or coproduct of copper mining. 

Molybdenum deposits result from granitic magmas that form large bodies of intrusive rock 

and are broadly classified into two types of deposits on the basis of how the deposits formed. The 

first, the Climax type, is a high-grade, fluorine-rich porphyry deposit and is extremely rare. All 13 

known Climax-type deposits are large, and all are found in the western United States. The second, 

a low-fluorine type, is closely related to porphyry copper deposits; these types of deposits are found 

primarily in western Canada and the northwestern United States. The two types are mined by both 

open-pit and underground methods. The United States produces significant quantities of molybdenum

from mines in Colorado, Idaho, Nevada, and New Mexico. At one time, the Climax mine in 

Colorado was the largest molybdenum mine in the world. In addition, mines in Arizona, Nevada, 

New Mexico, Montana, and Utah produce molybdenum as a byproduct of copper production. 

How Do We Use Molybdenum?

Approximately two-thirds of the molybdenum 

produced in 2008 was used in the production of alloy steels 

and superalloys. Stainless steels made with molybdenum 

have the strength and corrosion resistance needed for use 

in water distribution systems; food handling and chemical 

processing equipment; and home, hospital, and laboratory 

devices. Because of their strength and toughness, 

molybdenum alloy steels are used to make automotive 

parts, construction equipment, and gas transmission 

pipes. Molybdenum’s important alloying properties have 

given it a significant role in modern industrial technology, 

which increasingly requires materials that are functional 

under high stress, expanded temperature ranges, and 

highly corrosive environments. Without molybdenum as 

an alloying metal, the superstrength steel used in heavy 

construction (such as in skyscrapers and bridges) would 

be more costly; in some instances, the increased weight 

of alternative materials with equivalent strengths would 

render construction unmanageable or even impossible. 

Other significant uses of molybdenum are as a refractory 

metal (a metal that is exceptionally resistant to heat) and 

in numerous chemical applications, including as catalysts, 

lubricants, and pigments.

42

Mo

95.94 molybdenum

[Kr]5s14d5

As part of a broad mission to 

conduct research and provide 

information on nonfuel mineral 

resources, the U.S. Geological 

Survey (USGS) supports science 

to understand

• How and where molybdenum 

resources form and 

concentrate in the Earth’s 

crust

• How molybdenum resources 

interact with the environment 

to affect human and 

ecosystem health

• Trends in the supply and 

demand for molybdenum 

in the domestic and 

international markets

• Where future molybdenum 

resources might be found

Why is this information 

important? Read on to learn 

about molybdenum and the 

important role it plays in the 

ional economy, national 

urity, and lives of Americans 

ry day. 

nat

sec

eve

Molybdenum, whose chemical symbol is Mo, was first recognized as an element in 1778. Until 

at time, the mineral molybdenite—the most important source of molybdenum—was believed 

 be a lead mineral because of its metallic gray color, greasy feel, and softness. In the late 19th 

ntury, French metallurgists discovered that molybdenum, when alloyed (mixed) with steel in small 

uantities, creates a substance that is remarkably tougher than steel alone and is highly resistant to 

eat. The alloy was found to be ideal for making tools and armor plate. Today, the most common 

se of molybdenum is as an alloying agent in stainless steel, alloy steels, and superalloys to enhance 

ardness, strength, and resistance to corrosion.

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Alloy steels and superalloys made 

with molybdenum are very strong and 

corrosion resistant. Above, white-hot 

steel is being poured at the Allegheny 

Ludlum Steel Corp. in Brackenridge, Pa. 

Photograph by Albert T. Palmer.

Printed on recycled paper 
How Do We Ensure Adequate Supplies of Molybdenum for the Future?

Molybdenum is one of the few metals for which the 

United States has abundant domestic resources. Because of the 

abundance and versatility of molybdenum, current industrial 

research seeks to develop new materials that benefit from the 

alloying properties of molybdenum. In 2007, 57 percent of 

the U.S. molybdenum supply and 61 percent of the worldwide 

molybdenum supply were produced as a byproduct of copper 

mining. Short- to medium-term changes in copper prices 

can influence the availability of molybdenum. For example, 

copper mining activity may drop suddenly in response to 

reduced metal prices, which in turn reduces the total amount of 

molybdenum that is produced. Although primary molybdenum 

mines can fill this market gap between byproduct production 

and overall demand, they have a limited ability to increase 

their production rate to meet spikes in demand. Thus, although Climax-type molybdenum is mined underground at the Henderson overall molybdenum resources are robust, the availability of mine in Colorado. Photograph courtesy of Freeport-McMoRan molybdenum can be subject to market fluctuations. Copper & Gold Inc.

Did you know?... The Wills Saint Claire was the first automobile constructed with molybdenum steel.

 Photograph courtesy of Wills Saint Claire Automobile Museum, Marysville, Mich.

Molybdenite does not occur in 

nature as a free metal. Instead, it is 

found in combination with sulfur 

and oxygen and other metals 

in as many as 13 minerals. 

The major ore from which 

molybdenum is extracted is 

molybdenite (shown to the left), 

which is a soft, metallic-gray 

mineral whose name is derived 

from the Greek word molydbos, 

meaning lead, because it was 

initially mistaken for lead.

For More Information

• On production and consumption of molybdenum: The USGS Mineral Resources Program is the sole Federal 

 http://minerals.usgs.gov/minerals/pubs/commodity/ provider of research and information on molybdenum and other 

 molybdenum/ nonfuel mineral resources. For more information contact:

Mineral Resources Program Coordinator • On Climax-type molybdenum deposit models: U.S. Geological Survey http://pubs.usgs.gov/of/2009/1215/ MS 913 National Center 42

• On low-fluorine-type molybdenum deposit models: Reston, VA 20192

 http://pubs.usgs.gov/of/2009/1211/ Mo

Telephone: 703-648-6100 1 5 [Kr]5s 4d

Fax: 703-648-6057 molybdenum

95.94

E-mail: minerals@usgs.gov

Text prepared by S.J. Kropschot. Graphics and design by Linda Masonic Home page: http://minerals.usgs.gov

Did you know?... Molybdenum pigments provide the red-yellow to bright reddish-orange color found in paints, inks, 

 plastics, and rubber materials.

Did you know?... Molybdenum grease is a high-load-bearing waterproof grease used in elevator safety brake shoes. 

 Molybdenum is also used as a solid lubricant and as a catalyst in the refining of petroleum.

Research designed to better understand the geologic 

processes that produce molybdenum and other mineral deposits 

is an important component of the USGS Mineral Resources 

Program. This research provides essential information for 

mineral-resource assessments of public lands and for economic 

forecasting of the global availability of critical commodities.

In 2008, the USGS reported reserves of 2.7 million metric 

tons of molybdenum in the United States and an estimated 

6 million tons of molybdenum reserves in the rest of the world. 

The leading producers in 2008 were the United States, China, 

Chile, Peru, and Canada.