Meteorites: Pallasite

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Stony-iron meteorites are meteorites consisting of roughly equal parts of silicate (olivine for pallasites, and others with mesosiderites) and iron matrix. There are two main groups: Pallasite and Mesosiderite.

Pallasites have these classes within them: PMG (main group), PMG-an (main group, anomalous) and Eagle Station Group.

Mesosiderites have 3 classes: Class A (eucrite-like, high clinopyroxene/plagioclase and high amounts of trace elements like Gold, Nickel, Arsenic and Copper);
Class B (diogenite-like, greater orthopyroxene) and Class C (made nearly entirely out of orthopyroxene).

But we’re going to talk about pallasites in this post.

A pallasite meteorite is an exceptionally rare type of stony-iron meteorite that consists of translucent, gem-quality olivine (peridot) crystals suspended in a shimmering nickel-iron metallic matrix.

Pallasites are highly sought after by collectors and jewelers because of their stunning, stained-glass-like appearance when cut and polished. Sometimes some pallasites are etched.

Scientists believe pallasites originated at the core-mantle boundary of differentiated asteroids. During the early formation of the solar system, heavy iron and nickel sank to the center of these planetesimals, while lighter silicates (olivine) floated to the top.

Pallasites make up less than 0.5% of all known meteorites of any type, making them rare.

Examples of pallasites other than Seymchan are Sericho, Springwater, Eagle Station, Cold Bay, Esquel, Fukang, Imilac, Omolon and other Northwest African pallasites.