Identification guide · Sulfide Minerals
How to Identify Molybdenite
Molybdenite is usually lead gray and bluish gray with a metallic luster and is opaque. It has a Mohs hardness of 1.25. A fingernail (Mohs 2.5) scratches it easily. Its streak is bluish gray. It is most often confused with Stibnite, Pyrite, and Anthracite; the tests below separate them.
Molybdenite identification checklist
| Color | Lead gray, Bluish gray | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Metallic | Turn it under a lamp: a true metallic shine reflects like polished metal and stays opaque at thin edges. |
| Transparency | Opaque | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 1.25 | A fingernail (Mohs 2.5) scratches it easily. |
| Streak | Bluish gray | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Perfect on {0001} | |
| Fracture | Uneven | |
| Specific gravity | 4.7 | Very heavy, metallic heft (specific gravity about 4.7). |
| Crystal system | Hexagonal |
Molybdenite look-alikes and how to tell them apart
Both sit near Mohs 1.25, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Molybdenite vs Stibnite →
Pyrite is harder (Mohs 6.5) than Molybdenite (Mohs 1.25), so Pyrite will scratch Molybdenite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Molybdenite vs Pyrite →
Anthracite is harder (Mohs 2.5) than Molybdenite (Mohs 1.25), so Anthracite will scratch Molybdenite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Molybdenite vs Anthracite →
Aluminum is harder (Mohs 2.75) than Molybdenite (Mohs 1.25), so Aluminum will scratch Molybdenite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
Field tips
- Look for a soft, bluish lead-gray metallic mineral that feels greasy and forms flexible flakes.
- It is extremely soft, marking paper and bending into thin nonelastic plates along its perfect cleavage.
- Distinguish it from graphite by its bluish-gray streak on glazed porcelain and higher density.
Molybdenite identification FAQ
How can you tell if a rock is Molybdenite?
Check the color (lead gray and bluish gray), the metallic luster, a Mohs hardness of 1.25 and a bluish gray streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Molybdenite?
Molybdenite has a Mohs hardness of 1.25. A fingernail (Mohs 2.5) scratches it easily.
What is the difference between Molybdenite and Stibnite?
Molybdenite (Mohs 1.25, metallic luster) and Stibnite (Mohs 2, metallic luster) look alike, but hardness, streak and heft usually separate them. See the full Molybdenite vs Stibnite comparison for a side-by-side table.
Is Molybdenite worth anything?
Entry-level Molybdenite specimens sell for around $8, typical collector pieces about $45, and premium examples $250 or more depending on size, quality and locality.
What color is Molybdenite?
Molybdenite is most often lead gray and bluish gray. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
