Identification guide · Silicate Minerals
How to Identify Serpentine
Serpentine is usually green, yellowish green, and olive with a greasy luster and is translucent. It has a Mohs hardness of 3.5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is white. It is most often confused with Serpentinite, Mimetite, and Phlogopite; the tests below separate them.
Serpentine identification checklist
| Color | Green, Yellowish green, Olive, Black, White | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Greasy | Compare a fresh surface with glass and metal; this luster is softer than either. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 3.5 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None visible in massive material | |
| Fracture | Conchoidal to splintery | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.6 | Ordinary rock-like heft (specific gravity about 2.6), similar to quartz. |
| Crystal system | Monoclinic |
Serpentine look-alikes and how to tell them apart
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Serpentine vs Serpentinite →
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Serpentine vs Mimetite →
Both sit near Mohs 3.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Serpentine vs Phlogopite →
Serpentine is harder (Mohs 3.5) than Pyrophyllite (Mohs 1.5), so Serpentine will scratch Pyrophyllite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Serpentine vs Pyrophyllite →
Field tips
- Look for mottled green color, a greasy or waxy luster, and a smooth, slippery feel.
- Serpentine is fairly soft and can be scratched by a steel knife.
- Massive serpentine can mimic jade; jade is notably harder and tougher.
Serpentine identification FAQ
How can you tell if a rock is Serpentine?
Check the color (green, yellowish green, olive, and black), the greasy luster, a Mohs hardness of 3.5 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Serpentine?
Serpentine has a Mohs hardness of 3.5. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Serpentine and Serpentinite?
Serpentine (Mohs 3.5, greasy luster) and Serpentinite (Mohs 2.5–4, greasy, waxy, silky luster) look alike, but hardness, streak and heft usually separate them. See the full Serpentine vs Serpentinite comparison for a side-by-side table.
Is Serpentine worth anything?
Entry-level Serpentine specimens sell for around $5, typical collector pieces about $40, and premium examples $250 or more depending on size, quality and locality.
What color is Serpentine?
Serpentine is most often green, yellowish green, olive, and black. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
