Comparison · Metals & Alloys
Aluminum vs Nickel
Aluminum and Nickel are easy to confuse because both are metals & alloys. 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. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Aluminum and Nickel
- 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.
- Streak color differs: Aluminum leaves a silvery gray streak on unglazed porcelain, Nickel leaves gray.
- Both look metallic, so compare color, tarnish and weight rather than shine.
- Nickel feels noticeably heavier for its size (specific gravity 8.9 versus 2.7 for Aluminum).
- They overlap in gray, but Nickel also comes in yellow.
Aluminum vs Nickel properties
| Property | Aluminum | Nickel |
|---|---|---|
| Type | Metals & Alloys | Metals & Alloys |
| Mohs hardness | 2.75 | 4 |
| Luster | metallic | metallic |
| Streak | Silvery gray | Gray |
| Transparency | opaque | opaque |
| Specific gravity | 2.7 | 8.9 |
| Crystal system | varies | varies |
| Common colors | Silver, Light gray, Matte gray | Silver, Gray, Slightly yellow silver |
| Rarity | common | common |
| Typical specimen value | $1–$80+ | $1–$120+ |
Which is more valuable?
Nickel is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Aluminum, and premium Nickel can reach $120 or more.
About Aluminum
Aluminum is a lightweight silvery metal used in cans, foil, tools, frames, cookware, and many everyday objects. It is not usually found as native metal in nature, but it is a common visible material in manufactured scans.
About Nickel
Nickel is a hard silvery metal used in plating, coins, stainless steel, batteries, magnets, jewelry alloys, and industrial alloys.
Aluminum vs Nickel FAQ
Is Aluminum the same as Nickel?
No. Both are metals & alloys, but they are distinct species with different hardness, streak or luster. 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.
How can you tell Aluminum from Nickel?
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. Streak color differs: Aluminum leaves a silvery gray streak on unglazed porcelain, Nickel leaves gray. Both look metallic, so compare color, tarnish and weight rather than shine.
Which is harder, Aluminum or Nickel?
Nickel is harder: Mohs 4 against Mohs 2.75 for Aluminum.
Which is more valuable, Aluminum or Nickel?
Nickel is usually the more valuable of the two: a typical collector specimen runs about $15 against $10 for Aluminum, and premium Nickel can reach $120 or more.
