Identification guide · Metals & Alloys
How to Identify Nickel
Nickel is usually silver, gray, and slightly yellow silver with a metallic luster and is opaque. It has a Mohs hardness of 4. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Its streak is gray. It is most often confused with White Gold, Aluminum, and Brass; the tests below separate them.
Nickel identification checklist
| Color | Silver, Gray, Slightly yellow silver | 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 | 4 | A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. |
| Streak | Gray | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | None | |
| Fracture | Ductile to uneven | |
| Specific gravity | 8.9 | Very heavy, metallic heft (specific gravity about 8.9). |
Extra tests for Nickel
Magnet test. Magnetic: a magnet sticks firmly.
Nickel look-alikes and how to tell them apart
Nickel is harder (Mohs 4) than White Gold (Mohs 3), so Nickel will scratch White Gold and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Nickel vs White Gold →
Nickel is harder (Mohs 4) than Aluminum (Mohs 2.75), so Nickel will scratch Aluminum and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Nickel vs Aluminum →
Both sit near Mohs 4, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Nickel vs Brass →
Nickel is harder (Mohs 4) than Bronze (Mohs 3), so Nickel will scratch Bronze and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
Field tips
- Look for a silvery metal with a slightly warm gray cast.
- Nickel plating can be bright and smooth on hardware or jewelry.
- Nickel can be magnetic in some forms.
- Common objects include coins, plated hardware, batteries, and alloy parts.
Nickel identification FAQ
How can you tell if a rock is Nickel?
Check the color (silver, gray, and slightly yellow silver), the metallic luster, a Mohs hardness of 4 and a gray streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Nickel?
Nickel has a Mohs hardness of 4. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
What is the difference between Nickel and White Gold?
Nickel (Mohs 4, metallic luster) and White Gold (Mohs 3, metallic luster) look alike, but hardness, streak and heft usually separate them. See the full Nickel vs White Gold comparison for a side-by-side table.
Is Nickel worth anything?
Entry-level Nickel specimens sell for around $1, typical collector pieces about $15, and premium examples $120 or more depending on size, quality and locality.
What color is Nickel?
Nickel is most often silver, gray, and slightly yellow silver. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
