Ungrouped Achondrites
Ungrouped achondrites are rare igneous meteorites that do not fit into established classification groups, often representing unique parent bodies.
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Ksar Ghilane 022 Ungrouped Achondrite Meteorite Slice, Achondrite-ung, 1.75g, Augite-Rich Matrix -
Erg Chech 002 Ungrouped Achondrite Meteorite Individual, Achondrite-ung, 0.80g, Andesitic Crust Fragment -
Ksar Ghilane 022 Ungrouped Achondrite Meteorite Slice, achondrite-ung, 2.11g, Augite-Rich Differentiated Material -
Ksar Ghilane 022 Ungrouped Achondrite Meteorite End Cut, Achondrite-ung, 9.07g, Augite-Dominant Interior -
Ksar Ghilane 022 Ungrouped Achondrite Meteorite Slice, achondrite-ung, 2.33g, Augite-Dominated Matrix -
Bir Ounane 001 Achondrite-prim Meteorite Slice, Ungrouped, 6.46g, Polished Primitive Crust
Ungrouped achondrites are differentiated stony meteorites that do not match any established achondrite group. They come from parent bodies that have not yet been linked to a recognized clan, making each one a window into an otherwise unknown asteroid or planetesimal. Unless specifically stated in the listing, specimens in this collection are Meteoritical Bulletin classified.
How we verify ungrouped achondrites are real
Every specimen is tied to a Meteoritical Bulletin entry, the official global registry of classified meteorites maintained by the Meteoritical Society. Ungrouped status itself is assigned through formal classification: an accredited laboratory measures oxygen isotopes, mineralogy, and trace elements and determines that the specimen does not fit any known group. The Bulletin record is the definitive confirmation. Read more: The Meteoritical Bulletin Explained.
Why ungrouped specimens matter
Unique parent bodies. Each ungrouped achondrite likely represents a distinct asteroid or planetesimal not sampled by any other known meteorite, giving collectors and researchers a piece of an otherwise unrepresented world.
Scientific value. Ungrouped specimens often drive the discovery of new groups. Several meteorite groups recognized today began as a single ungrouped specimen that was later joined by pairs and clan members.
Rarity. Because ungrouped status requires that no peer specimens exist, these meteorites are by definition rare. Many are known from a single recovered mass.
Frequently asked questions
What does ungrouped mean? Ungrouped means the specimen has been classified as an achondrite but does not match the chemistry or mineralogy of any established group such as HED, ureilite, aubrite, lunar, or Martian. Read more: What Is an Achondrite?
How can I tell an ungrouped achondrite is real? The Meteoritical Bulletin entry is the definitive proof. Each entry includes the laboratory that performed the classification, the data that established ungrouped status, and the type specimen mass. Read more: How Can You Tell if a Meteorite Is Real?
Are ungrouped achondrites magnetic? It depends entirely on the parent body. Some ungrouped achondrites contain free metal and are weakly magnetic, others contain none and show no magnetic response. Read more: Are Meteorites Magnetic?
Are ungrouped achondrites a good investment? Specimens that later become type material for newly recognized groups can appreciate substantially. Most ungrouped achondrites remain niche, scientifically interesting collectibles. Read more: How Much Do Meteorites Cost?
Are these specimens authenticated? Unless otherwise noted, every ungrouped achondrite here has a Meteoritical Bulletin record and ships with a Treasure Coast Meteorite Co. certificate of authenticity.
See also: HED Meteorites · Lunar Meteorites · Martian Meteorites · Stony Meteorites · Types of Meteorites · Are Meteorites Illegal to Own?