Primitive achondrites, including winonaites, acapulcoites, lodranites, brachinites and ungrouped types, recrystallized and began to melt on their parent bodies without fully differentiating, keeping a near-chondritic composition.
Offered by Treasure Coast Meteorite Co., IMCA Member #3323, with documented classification and provenance when applicable.
Primitive achondrites record an early stage of planet building. Their parent bodies were heated until they recrystallized and began to melt, but they never separated fully into core, mantle and crust the way the parent bodies of the eucrites or angrites did. The result is a meteorite with the crystalline texture of an achondrite and a composition that still sits close to a chondrite. Unless specifically stated in the listing, specimens in this collection are Meteoritical Bulletin classified.
Every classified specimen is tied to a Meteoritical Bulletin entry, the official registry of meteorite names maintained by the Meteoritical Society. Primitive achondrites are among the harder groups to classify, because the named groups overlap in texture and are separated mainly by mineral chemistry. Where the Bulletin records how a classification was reached, or flags uncertainty about it, the listing says so. Read more: The Meteoritical Bulletin Explained
Winonaites are named for the Winona meteorite, found in Arizona. They are fine grained and close to chondritic in mineralogy, and they are widely thought to share a parent body with the silicate inclusions found in IAB complex iron meteorites.
Acapulcoites and lodranites are named for the Acapulco meteorite from Mexico and the Lodran meteorite from Pakistan. The Meteoritical Bulletin groups them as a single family. Acapulcoites are finer grained and experienced less melting, while lodranites are coarser grained and lost more of their melt.
Brachinites are named for the Brachina meteorite from South Australia. They are dominated by olivine and form their own group within the primitive achondrites.
Ungrouped primitive achondrites are classified in the Bulletin as Achondrite-prim or Achondrite-prim-ung when their chemistry does not match any established group.
Why are they called primitive? Because their parent bodies stopped partway through melting. They keep more of the original chondritic composition than fully melted achondrites do, which makes them a record of the earliest heating of small bodies in the solar system. Read more: What Is an Achondrite?
How many primitive achondrites are there? The Meteoritical Bulletin database lists 426 entries in its primitive achondrite category as of September 2026, including 109 winonaites, 101 lodranites, 97 acapulcoites and 70 brachinites. These are counts of database entries rather than separate falls, because pieces of the same meteorite can be listed under different names until they are paired. Read more: How Rare Are Meteorites?
Are ureilites primitive achondrites? Some researchers group them together, but the Meteoritical Bulletin lists ureilites as a separate category. This collection follows the Bulletin, so ureilites are not included here.
Are primitive achondrites magnetic? Many contain iron-nickel metal and will respond to a strong magnet, but the amount of metal varies between groups and between individual specimens. Read more: Are Meteorites Magnetic?
How can I tell a primitive achondrite is real? A classified specimen has a Meteoritical Bulletin entry that can be checked directly, and it should be sold with that name and documentation. Read more: How Can You Tell if a Meteorite Is Real?
Are these specimens authenticated? Unless otherwise noted, every specimen here has a Meteoritical Bulletin record and ships with a Treasure Coast Meteorite Co. certificate of authenticity.
See also: Ungrouped Achondrites · HED Meteorites · Stony Meteorites · What Is an Achondrite? · How Are Meteorites Classified? · Types of Meteorites
