NWA METEORITES EXPLAINED
Meteorite Science
NWA stands for Northwest Africa. The designation appears on thousands of meteorites recovered from the Sahara Desert and Sahel regions over the past three decades. Understanding what NWA means, and what it does not mean, helps collectors evaluate these specimens accurately.
What the NWA Designation Means
When a meteorite is recovered in northwest Africa without a specific verified locality, meaning no precise GPS coordinates or confirmed find site, it receives the designation NWA followed by a sequential number assigned by the Meteoritical Bulletin upon classification. The number is simply the next available in a running sequence and has no scientific significance beyond providing a unique identifier. NWA 18048 was the 18,048th meteorite entry assigned an NWA designation in the Bulletin.
Why So Many Meteorites Come from Northwest Africa
Northwest Africa has become the most productive meteorite recovery region in the world outside Antarctica for several practical reasons. The Sahara Desert provides ideal preservation conditions: minimal rainfall prevents rapid weathering, sparse vegetation leaves the ground surface exposed, and the light-colored substrate makes dark meteorites visually distinctive.
The region also has an enormous surface area with millions of years of accumulated meteorite material. Meteorites that fell thousands of years ago remain on or near the surface, having been gradually exposed by wind erosion that removes the overlying sediment. Systematic searching by experienced hunters in favorable terrain can recover large numbers of specimens per expedition.
Before northwest African recovery programs began in the 1990s, the total number of classified meteorites in the world was measured in the thousands. The NWA program, combined with Antarctic recovery programs, has since expanded that to approximately 70,000 classified specimens, transforming meteorite science.
Most NWA meteorites pass through local nomadic populations and professional meteorite hunters before entering the dealer and classification pipeline. The supply chain is well-established and the material is genuine, but precise provenance within the region is often undocumented by the time specimens reach classifiers.
Classification and Authenticity
An NWA meteorite with a Meteoritical Bulletin entry has been scientifically classified by a qualified researcher using laboratory analysis, the same process applied to all other classified meteorites. The NWA designation does not indicate lesser authenticity, lower scientific value, or imprecise classification. It only means the recovery location was not precisely documented.
Some of the most scientifically significant meteorites ever found carry NWA designations. NWA 7034, known as "Black Beauty," is a polymict Martian breccia unlike any other known meteorite and one of the most studied specimens in planetary science. Numerous lunar meteorites with NWA numbers are among the most important specimens in current research collections.
Whether an NWA meteorite has a Meteoritical Bulletin entry is what matters. An NWA number alone, without a corresponding Bulletin entry, means the specimen has not been formally classified. Always verify the Bulletin entry for any NWA meteorite before purchasing. The database is publicly accessible at lpi.usra.edu/meteor/metbull.php.
Paired Meteorites
Many NWA meteorites are paired, meaning multiple specimens with different NWA numbers are determined through geochemical analysis to come from the same original meteorite fall. Pairing is established based on matching mineralogy, chemistry, and isotopic signatures, and is recorded in the Meteoritical Bulletin.
Pairing affects total known weight calculations. If two NWA specimens are paired, the combined weight of both is attributed to a single fall event. This matters for rarity assessment: ten specimens that all pair together represent one meteorite, not ten independent events.
Collectors sometimes seek unpaired specimens for their independent provenance, but paired specimens are not scientifically less valuable. From a collecting standpoint, the relevant question is the total number of known fragments and combined mass, not simply whether a specimen is paired.
For more on how pairing affects your purchasing decisions, see the Meteoritical Bulletin Explained guide, which walks through how to read pairing information in a Bulletin entry.
NWA Meteorites in Our Collection
A significant portion of our inventory carries NWA designations, including eucrites, diogenites, carbonaceous chondrites, lunar meteorites, and Martian meteorites. Every NWA specimen we sell includes the direct Meteoritical Bulletin link for independent verification. Where pairing information exists, we disclose it in the listing.
Related Reading
Browse NWA Specimens
Frequently Asked Questions
Does NWA mean the meteorite is less valuable or less authentic?
No. NWA means the recovery location was not precisely documented, not that the specimen is less authentic or scientifically less significant. Some of the most important meteorites in planetary science carry NWA designations. A Meteoritical Bulletin entry confirms the classification regardless of the recovery region designation.
How do I verify an NWA meteorite's classification?
Search the full name at lpi.usra.edu/meteor/metbull.php. Enter the NWA number, for example "Northwest Africa 17706" or "NWA 17706," and confirm the classification, total known weight, and any pairing notes match what the seller states. This takes under a minute and can be done before or after purchase.
What countries do NWA meteorites come from?
The NWA designation covers Morocco, Algeria, Libya, Mali, Mauritania, Niger, and surrounding northwest African regions. Many specimens are purchased through dealers in Morocco or Algeria but the precise find country is often undocumented. Where a specific country is known, some meteorites receive a named locality designation rather than NWA.
What does it mean if an NWA meteorite is unclassified?
It means the specimen has not been formally analyzed and accepted into the Meteoritical Bulletin. Unclassified NWA material can still be genuine meteorite material from the same recovery regions as classified specimens, but its scientific identity has not been formally established. Reputable dealers clearly distinguish classified from unclassified material.
What is total known weight and why does pairing affect it?
Total known weight (TKW) is the combined mass of all documented material from a single meteorite fall. When specimens are paired, their masses are combined into one TKW figure. A low TKW indicates rarity regardless of whether that mass is distributed across one specimen or several paired fragments.
