Molybdenite, also known as “Moly Ore”, is a mineral of molybdenum disulfide. It is a very soft metallic mineral. It
can be easily confused with graphite, but not with many other minerals. Graphite is a darker black-silver color and
has a black-gray to brown-gray streak. Molybdenite has a bluish-silver color and a blueish silver streak. Prior to
the discovery of molybdenum as a separate element in 1778 by Karl Wilhelm Scheele, Molybdenite was thought
to be Graphite or a lead ore.
Molybdenite is composed of alternating layers molybdenum and sulfur. The sulfur's layers are strongly bonded to
the molybdenum, but are not strongly bonded to other sulfur ions. This produces the effect of softness and allows
for perfect cleavage. It is soft enough to leave a mark on paper and it has a “greasy” feeling surface due to its
extreme softness. Molybdenite is a very high luster mineral and is a favorite and interesting mineral to have in any
It is named for the molybdenum content (which gets its name from the Greek word “molybdos”, meaning “lead,”
referring to its lead-like color and metallic luster). Molybdenite is the most abundant molybdenum-bearing
mineral. It occurs as unique crystal formations in many localities including the United States, Canada, Norway,
Russia, Germany, Morocco, Australia, and Japan.
It has been found on rare occasion in meteorites. It is commonly found in “contact metamorphosed” limestone,
pegmatites, granites, fine grained igneous rock, disseminated porphyry deposits and in high-temperature
hydrothermal vein deposits. (Metamorphic rocks are formed when sedimentary and igneous rocks become
changed, or metamorphosed by being in contact with hot magma or lava. This is called contact metamorphism.)
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.
|Item # 1MOLYB07169462
Molybdenite in Quartz matrix
from the Molly Hill Mine,
|This specimen was collected in the 1960’s and was procured from a mineral
dealer in Amos, Quebec, Canada. The original collector made the tag shown in
the photos that comes with the specimen. It is from the Molly Hill Mine (also
known as Moly Hill Mine) operated by the Moly Hill Mining Corporation Ltd. from
1964 to 1968. The mine is located in La Motte, Abitibi RCM, Abitibi-
Témiscamingue, Québec, Canada This piece has three protruding Molybdenite
crystals (19 x 11mm, 11 x 7mm, 10 x 7mm) and one other almost flush with the
matrix quartz (14 x 9mm).
This specimen weighs 3.12 oz or 0.196 lb. (88.5g)
and measures 2.3 x 1.9 x 1.6 inches (59 x 48 x 41mm)