RocksdayAdamite vs Scorodite
The quickest way to tell Adamite from Scorodite: Adamite feels noticeably heavier for its size (specific gravity 4.3–4.5 vs 3.1–3.3).
A zinc arsenate forming lime-green crystal sprays that glow vivid green under UV.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
A hydrated iron arsenate that forms pale green or blue crystals where arsenic ores weather.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Quick tests
- Heft: Adamite feels noticeably heavier for its size (specific gravity 4.3–4.5 vs 3.1–3.3).
Key differences
- Adamite is usually brighter yellow-green and is a zinc arsenate.
Side by side
| Property | Adamite | Scorodite |
|---|---|---|
| Type | Mineral | Mineral |
| Mohs hardness | 3.5 | 3.5–4 |
| Luster | Vitreous | Vitreous to earthy |
| Streak | White | White |
| Colors | Yellow, Green, Purple | Green, Blue, Gray, Brown |
| Crystal system | Orthorhombic | Orthorhombic |
| Specific gravity | 4.3–4.5 | 3.1–3.3 |
| Formula | Zn₂AsO₄(OH) | FeAsO₄·2H₂O |
| Found in | Ojuela mine, Mapimí, Mexico; Laurium, Greece | Tsumeb, Namibia; Ojuela mine, Mapimí, Mexico |
Properties that are the same for both are grayed out.
How to identify adamite
- Lime-yellow-green crystals on brown limonite.
- Glows bright green under UV light.
- Soft — a knife scratches it.
Crystal system: Orthorhombic
Full Adamite guide →How to identify scorodite
- Pale green, blue-green or gray pyramidal crystals or crusts.
- Hardness about 3.5–4.
- On or near arsenopyrite or other arsenic minerals.
Crystal system: Orthorhombic
Full Scorodite guide →More comparisons
Frequently asked questions
What is the difference between adamite and scorodite?
Adamite is a mineral with a Mohs hardness of 3.5 and a vitreous luster, usually yellow, green or purple. Scorodite is a mineral (FeAsO₄·2H₂O) with a Mohs hardness of 3.5–4 and a vitreous to earthy luster, usually green, blue, gray or brown.
How can you tell adamite from scorodite?
Adamite feels noticeably heavier for its size (specific gravity 4.3–4.5 vs 3.1–3.3). Adamite is usually brighter yellow-green and is a zinc arsenate.
Could you tell them apart from a blurry close-up?
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