RocksdayNative Copper vs Gold
How to tell them apart
Copper as a pure metal, often in branching, tree-like masses. Fresh surfaces are salmon-pink; old ones tarnish brown or green.
Photo: Native_Copper_Macro_Digon3.jpg: “Jonathan Zander (Digon3)" derivative work: Materialscientist (talk), CC BY-SA 3.0
A native metal that never tarnishes. In nature it occurs as nuggets, flakes in stream gravel and wires in quartz veins.
Photo: Alchemist-hp (talk) www.pse-mendelejew.de, CC BY-SA 3.0 de
Quick tests
- Streak (rub on unglazed porcelain): Native Copper leaves a copper red streak; Gold leaves golden yellow.
- Heft: Gold feels noticeably heavier for its size (specific gravity 15.5–19.3 vs 8.9–8.95).
Key differences
- Gold is yellow and heavier still.
Side by side
| Property | Native Copper | Gold |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 2.5–3 | 2.5–3 |
| Luster | Metallic | Metallic |
| Streak | Copper red | Golden yellow |
| Colors | Orange, Brown, Green | Gold |
| Crystal system | Cubic | Cubic |
| Specific gravity | 8.9–8.95 | 15.5–19.3 |
| Formula | Cu | Au |
| Found in | Keweenaw Peninsula, Michigan; Arizona | Witwatersrand, South Africa; Carlin Trend, Nevada |
Properties that are the same for both are grayed out.
How to identify native copper
- Copper-red where scratched; brown or green tarnish elsewhere.
- Heavy and malleable — it bends.
- Branching, wiry or nugget shapes.
- Shiny copper-red streak.
Crystal system: Cubic
Full Native Copper guide →How to identify gold
- Extremely heavy — sinks instantly in a gold pan.
- Bends and flattens instead of breaking.
- Golden streak.
- Stays bright yellow in shade and sun alike.
Crystal system: Cubic
Full Gold guide →More comparisons
Could you tell them apart from a blurry close-up?
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