Comparison · Metals & Alloys
Iron vs Zinc
Iron and Zinc are easy to confuse because both are metals & alloys. Iron is harder (Mohs 4) than Zinc (Mohs 2.5), so Iron will scratch Zinc 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 Iron and Zinc
- Iron is harder (Mohs 4) than Zinc (Mohs 2.5), so Iron will scratch Zinc and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
- Streak color differs: Iron leaves a gray to dark gray streak on unglazed porcelain, Zinc leaves gray.
- Both look metallic, so compare color, tarnish and weight rather than shine.
- Iron feels noticeably heavier for its size (specific gravity 7.87 versus 7.14 for Zinc).
- They overlap in gray, but Iron also comes in brown.
Iron vs Zinc properties
| Property | Iron | Zinc |
|---|---|---|
| Type | Metals & Alloys | Metals & Alloys |
| Mohs hardness | 4 | 2.5 |
| Luster | metallic | metallic |
| Streak | Gray to dark gray | Gray |
| Transparency | opaque | opaque |
| Specific gravity | 7.87 | 7.14 |
| Crystal system | varies | varies |
| Common colors | Silver-gray, Dark gray, Rust brown | Bluish silver, Gray, Dull silver |
| Rarity | common | common |
| Typical specimen value | $1–$100+ | $1–$100+ |
Which is more valuable?
Typical specimens of Iron and Zinc trade in a similar range, around $10.
About Iron
Iron is a gray metallic element and the base metal for steel. In everyday scans it may appear as wrought iron, cast iron, raw metal, hardware, tools, or rusty objects.
About Zinc
Zinc is a bluish-silver metal used in galvanizing steel, die-cast objects, batteries, coins, hardware, and brass production.
Iron vs Zinc FAQ
Is Iron the same as Zinc?
No. Both are metals & alloys, but they are distinct species with different hardness, streak or luster. Iron is harder (Mohs 4) than Zinc (Mohs 2.5), so Iron will scratch Zinc and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not.
How can you tell Iron from Zinc?
Iron is harder (Mohs 4) than Zinc (Mohs 2.5), so Iron will scratch Zinc and not the other way round. A copper coin (Mohs 3.5) scratches it, but a fingernail does not. Streak color differs: Iron leaves a gray to dark gray streak on unglazed porcelain, Zinc leaves gray. Both look metallic, so compare color, tarnish and weight rather than shine.
Which is harder, Iron or Zinc?
Iron is harder: Mohs 4 against Mohs 2.5 for Zinc.
Which is more valuable, Iron or Zinc?
Typical specimens of Iron and Zinc trade in a similar range, around $10.
