The facts
What molybdenite actually is
Mineralogically, molybdenite is molybdenite — MoS₂, crystallising in the hexagonal system.
The colour is caused by metallic lead-grey with a bluish tint; layered structure like graphite. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer gives nothing, because the material is opaque, and the specific gravity sits near 4.62–5.06; cleavage is perfect basal {0001}; flexible, greasy to the touch.
Where molybdenite comes from
The recognised sources are Moly Hill and Mont Saint-Hilaire, Quebec, Canada, Climax Mine, Colorado, USA, Kingsgate, New South Wales, Australia and Azegour, Morocco.
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How molybdenite is treated
Untreated. Separated from graphite by its higher density and bluer tone, and by leaving a greenish-grey rather than black mark on paper. Soft, greasy and unworkable as a gem; a specimen and lubricant mineral.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What molybdenite is confused with
The usual confusions are Graphite, Galena, Hematite (specular) and Stibnite.
Because the material is opaque, refractive index is no help. Specific gravity around 4.62–5.06, hardness of 1–1.5, streak and magnification do the work instead.
What molybdenite is used for
Molybdenite is bought by mineral collecting, technical and precision components, heavy industry and metallurgy — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen, by the piece or by the tonne.
Durability and care
Molybdenite is 1–1.5 on the Mohs scale, with perfect basal {0001}; flexible, greasy to the touch cleavage.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What molybdenite costs
Indicative pricing for molybdenite is Specimens $15–$600.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is molybdenite treated, and how?
Untreated. Separated from graphite by its higher density and bluer tone, and by leaving a greenish-grey rather than black mark on paper. Soft, greasy and unworkable as a gem; a specimen and lubricant mineral.
Where does molybdenite come from?
Moly Hill and Mont Saint-Hilaire, Quebec, Canada, Climax Mine, Colorado, USA, Kingsgate, New South Wales, Australia and Azegour, Morocco. Origin affects price, so we name the locality rather than the country on every quote.
Is molybdenite hard enough to wear every day?
Not really. At 1–1.5 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does molybdenite cost?
Indicatively Specimens $15–$600. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is molybdenite confused with?
Most often Graphite, Galena, Hematite (specular) and Stibnite. Since the material is opaque, separation relies on specific gravity near 4.62–5.06, hardness and magnification.
What is molybdenite used for besides jewellery?
mineral collecting, technical and precision components, heavy industry and metallurgy. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for molybdenite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about molybdenite