Molybdenite

In short

Molybdenite is a lead-grey, metallic-looking, very soft mineral made of molybdenum and sulfur (MoS₂). It splits into thin, flexible flakes and leaves a grey mark on the fingers, which is why it is most often mistaken for graphite. It is the most important ore of molybdenum, a metal used mostly in steel and alloys.

Photos

How to recognise it

1. 1

   It is very soft (hardness 1–1.5): a fingernail scratches it, it leaves a grey mark on paper and fingers, and it feels greasy and slippery.

2. 2

   It is lead-grey with a metallic lustre and splits into thin, flexible flakes. The flakes bend but do not spring back.

3. 3

   What sets it apart from graphite is weight: its specific gravity is about 4.7, more than twice that of graphite (about 2.1–2.2). The streak is bluish grey (greenish grey in some sources), while graphite’s is black to steel-grey.

4. 4

   It mostly occurs in quartz veins or inside rocks such as granite, as leafy flakes, clusters or scattered grains, and is often accompanied by copper minerals such as chalcopyrite.

Myths and misconceptions

• MythMolybdenite is just another name for graphite.

  FactThey are separate minerals: graphite is made of carbon, molybdenite of molybdenum and sulfur. Both are soft, slippery grey minerals that mark paper, but molybdenite is more than twice as heavy. Because of this resemblance they were long confused, and not until Scheele’s work in 1778 was it understood that molybdenite is the ore of a separate element.

• MythMolybdenite is a lead ore.

  FactIt contains no lead; it is molybdenum disulfide (MoS₂). Its name comes from the Greek word for “lead” because it was long mistaken for lead ores.

Did you know?

Where is it found?

• Climax, Colorado, USA · Major depositAccording to Wikipedia, the Climax mine was the largest molybdenum mine in the world and for many years supplied three-fourths of the world's molybdenum
• Henderson mine, Clear Creek County, Colorado, USA · Major depositNorth America's largest primary (molybdenum-first) mine; in production since 1976
• Questa, New Mexico, USA · Known localityA molybdenum mine opened in 1916, closed permanently in 2014 because of low molybdenum prices and high operating costs
• Bingham Canyon mine, Utah, USA · Known localityA copper mine that yields molybdenum as a by-product (in 2005 the molybdenum it produced was worth more than its copper)
• Chuquicamata, Antofagasta, Chile · Major depositA huge copper mine; molybdenite occurs in quartz veins and molybdenum is a significant by-product. According to the USGS, Chile is the world's second-largest molybdenum producer
• Knaben, Agder, Norway · Historic sourceMolybdenite was mined here from 1885 to 1973; mining picked up after 1897, when adding molybdenum to steel proved useful for weapon making
• Luanchuan, Henan, China · Major depositAccording to Wikipedia the county has significant molybdenum and tungsten deposits; according to the USGS, China is the world's largest molybdenum producer (about 97 thousand tonnes in 2025)
• Başnayayla, Yozgat, Türkiye · Known localityAbout 15 km southwest of Yozgat, a low-grade molybdenum-copper mineralisation linked to granite; MTA investigated it by drilling and found it uneconomic (location approximate)

Locations are approximate to protect sites. Red dots mark places in Türkiye. Open in the big map →