RocksdayPallasite vs Peridotite
The quickest way to tell Pallasite from Peridotite: A magnet sticks to Pallasite but not to Peridotite.
A stony-iron meteorite: gemmy olivine crystals set in nickel-iron, widely interpreted as material from the boundary of an asteroid's core and mantle.
Photo: Doug Bowman, CC BY 2.0
A dense green rock of olivine and pyroxene — the main rock of Earth's upper mantle.
Photo: Shannon Heinle, CC0
Quick tests
- Magnet: A magnet sticks to Pallasite but not to Peridotite.
- Heft: Pallasite feels noticeably heavier for its size (specific gravity 4.5–7 vs 3.1–3.4).
- Luster: Pallasite looks metallic; Peridotite doesn't.
Key differences
- Peridotite is a rock of olivine without a metal network, and a magnet does not stick.
Side by side
| Property | Pallasite | Peridotite |
|---|---|---|
| Type | Igneous rock | Igneous rock |
| Mohs hardness | 4–7 | 6–7 |
| Luster | Metallic and vitreous | Granular |
| Streak | Gray | — |
| Colors | Green, Yellow, Gray, Silver | Green, Black, Brown |
| Crystal system / structure | Olivine crystals in nickel-iron | Coarse-grained (ultramafic) |
| Specific gravity | 4.5–7 | 3.1–3.4 |
| Found in | Brenham, Kansas; Esquel, Argentina | Samail ophiolite, Oman; Tablelands, Newfoundland |
Properties that are the same for both are grayed out.
How to identify pallasite
- Translucent green or yellow olivine in a metal network.
- A magnet sticks to the metal.
- Heavier than a terrestrial rock of the same size.
Structure: Olivine crystals in nickel-iron
Full Pallasite guide →How to identify peridotite
- Green, coarse and very heavy.
- Mostly glassy olivine grains.
- Weathers to a rusty brown crust.
Structure: Coarse-grained (ultramafic)
Full Peridotite guide →More comparisons
Frequently asked questions
What is the difference between pallasite and peridotite?
Pallasite is an igneous rock with a Mohs hardness of about 4–7 and a metallic and vitreous luster, usually green, yellow, gray or silvery. Peridotite is an igneous rock with a Mohs hardness of about 6–7 and a granular luster, usually green, black or brown.
How can you tell pallasite from peridotite?
A magnet sticks to Pallasite but not to Peridotite. Pallasite feels noticeably heavier for its size (specific gravity 4.5–7 vs 3.1–3.4). Pallasite looks metallic; Peridotite doesn't. Peridotite is a rock of olivine without a metal network, and a magnet does not stick.
Could you tell them apart from a blurry close-up?
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