Mesosiderite
Mesosiderite is meteorite (stony-iron, brecciated), (Fe-Ni metal + basaltic silicate breccia). In the hand, it rates 4 to 6 (mixed) on the Mohs scale, and it runs gray stone with silvery metal marbling and rusty weathered crust. A cosmic car crash in cross-section, angular gray rock fragments welded with swirled silvery nickel-iron, half metal, half stone, all chaos.
The geology.
Mesosiderite carries the formula (Fe-Ni metal + basaltic silicate breccia). It belongs to the, system. On paper it is meteorite (stony-iron, brecciated).
It sits at 4 to 6 (mixed) on the Mohs scale. The surface reads metallic patches in stony matrix. Light behaviour is opaque. Specific gravity runs 4.2 to 5.2. The streak is gray. It breaks with uneven; tough.
A cosmic car crash in cross-section, angular gray rock fragments welded with swirled silvery nickel-iron, half metal, half stone, all chaos.
Expect to see it as cut and polished slices, whole stones or end cuts.
The origins.
Rare falls and finds: Vaca Muerta (Chile), Estherville (Iowa, USA), NWA finds from the Sahara.
On value, the database notes: prized; rarer than iron meteorites, priced accordingly.
Traditional associations.
In energy work traditions, meteorites like mesosiderite carry cosmic-connection and resilience themes.
Recorded here because it is part of how this material is sold, not because it is a property of the material.
Spotting the real thing.
A cosmic car crash in cross-section, angular gray rock fragments welded with swirled silvery nickel-iron, half metal, half stone, all chaos.
Faked less than irons but misidentified often, XRF nickel confirmation and dealer classification papers are the standard.
| Looks like | How to tell them apart |
|---|---|
| Pallasite | The other stony-iron shows golden olivine gems in continuous metal, orderly where mesosiderite is jumbled |
| Iron meteorite | Irons are solid metal throughout with Widmanstätten etch patterns |
| Slag with metal prills | Slag has gas bubbles and no nickel; meteorites carry 5 to 10% nickel in their metal |
At-home tests.
None of these need a lab. A 10x loupe, good daylight and a steady hand cover most of what a buyer needs to know about mesosiderite.
| Test | What you should see |
|---|---|
| Magnet check | Strong magnet response |
| Cut face | metal networks through stone breccia |
| By eye | Nickel test or XRF confirms (no nickel = no meteorite) |
| By eye | No vesicles |
If these checks leave you unsure, that is what appraisers are for. Do not file, heat or soak a piece to find out.
Care & handling.
At 4 to 6 (mixed) on the Mohs scale this is a soft material. Keep it as a display piece, store it apart from harder stones, and skip daily-wear settings.
It breaks with uneven; tough, which is worth knowing before you set it or drop it.
Most damage happens during cleaning, not wearing. Avoid steamers, ultrasonic tanks and anything from under the sink.
A deeper look.
Extended detail on composition, sourcing, authentication and market value.
The physical record
The formula on record is (Fe-Ni metal + basaltic silicate breccia). Crystal system:,. Specific gravity: 4.2 to 5.2. Streak: Gray. Cleavage and fracture: Uneven; tough.
How it reaches the market
Rare falls and finds: Vaca Muerta (Chile), Estherville (Iowa, USA), NWA finds from the Sahara.
What it gets confused with
Pallasite: The other stony-iron shows golden olivine gems in continuous metal, orderly where mesosiderite is jumbled. Iron meteorite: Irons are solid metal throughout with Widmanstätten etch patterns. Slag with metal prills: Slag has gas bubbles and no nickel; meteorites carry 5 to 10% nickel in their metal.
What it is worth
Prized; rarer than iron meteorites, priced accordingly.
Where buyers get caught
Faked less than irons but misidentified often, XRF nickel confirmation and dealer classification papers are the standard.
One more thing
Mesosiderites likely record asteroid-on-asteroid collisions, molten core metal splashed into shattered crust and froze as this marbled wreckage.
An education-first guide.
There is nothing to buy on this page. Mesosiderite is not part of our catalogue, and the guide is here anyway because somebody searching the name deserves a straight answer.
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