NWA 18497 CVox3 Carbonaceous Chondrite Complete Individual 20.50g

A complete individual of NWA 18497, an oxidized CV3 carbonaceous chondrite

NWA 18497 belongs to the CV group of carbonaceous chondrites, primitive stony meteorites that preserve solids from the earliest stage of the solar system. This 20.50 gram stone is a complete individual, with no saw cuts and no polished face. Rounded chondrules show across its dark natural exterior, and remnants of fusion crust remain on parts of the surface.

The Meteoritical Bulletin lists NWA 18497 as CVox3 with a recorded mass of 725 grams in many pieces. It was classified by J. Garcia, ADARA, under the workname BMD 038.

Structure and features

Everything visible on this stone is natural surface. Remnants of fusion crust, dark and glossy, cover parts of the exterior, and chondrules stand out in relief across it in tan, orange and copper tones. Fine cracks cross the surface in places, some lined with orange-brown staining. The stone carries no coating.

The classification thin section, described in the Bulletin, shows well-defined chondrules in a dark, fine-grained, olivine-rich matrix. Chondrules have an apparent mean diameter of about 1.2 mm and are dominated by Type I chondrules, with Type II chondrules extremely scarce. Amoeboid olivine aggregates are present, and calcium-aluminum-rich inclusions (CAIs) range from submillimeter to almost a centimeter. The Bulletin records a low weathering grade.

Discovery and provenance

NWA 18497 carries a Northwest Africa name, used for meteorites from the region whose exact find site is not documented. The Bulletin records the year as 2024, and its writeup states the meteorite was purchased in 2024 from an Algerian dealer. Coordinates are recorded as unknown.

The Bulletin records the workname BMD 038 and lists the meteorite as submitted by Jose Garcia. J. Garcia at ADARA in the Canary Islands carried out the petrography and classification. A 20 gram type specimen is held at MUNA, the Museo de la Naturaleza y Arqueologia in Tenerife, and one thin section is held at ADARA. The Bulletin records the main mass with Brian McDonald. This 20.50 gram individual is one of the smaller pieces of NWA 18497 held by Treasure Coast Meteorite Co. The entry was approved on 27 March 2026 and is listed for Meteoritical Bulletin 115, which is in preparation and not yet a published volume.

Scientific context

CV chondrites are among the most studied carbonaceous chondrites. They are known for large chondrules, abundant matrix, amoeboid olivine aggregates and CAIs, the last being among the oldest dated solids formed in the solar system. Background on the wider family is set out in what is a chondrite.

The "ox" in CVox3 places NWA 18497 in the oxidized subgroup of the CV chondrites. The classifier assigned this on the mean nickel content of its sulfides and metal: sulfides average 4.1 wt% Ni and metal 65.8 wt% Ni. The "3" is the petrologic type, assigned on the strong compositional heterogeneity of its olivine and pyroxene. Chondrule olivine averages Fa8.6 and matrix olivine Fa49.9. How these designations are assigned is covered in how meteorites are classified.

What the research reports

The Meteoritical Bulletin's recommended classification for NWA 18497 is CVox3. Its writeup goes one step further and classifies the meteorite as CVoxA3, placing it in the Allende-like branch of the oxidized CV chondrites, on the basis of the criteria in the study below. The recommended class is what appears in this listing's title and metafields; the CVoxA assignment is given here as the writeup states it. Findings below come from the authors' own samples and methods and are given as the study states them.

Gattacceca, Bonal, Sonzogni and Longerey (2020)

J. Gattacceca, L. Bonal, C. Sonzogni and J. Longerey, CV chondrites: More than one parent body, Earth and Planetary Science Letters 547, 116467 (2020). This is the study the Bulletin writeup cites for the CVoxA assignment.

The authors studied 53 CV chondrites, sorting them into the reduced subgroup and the two oxidized subgroups, CVoxA and CVoxB. They concluded that the reduced and oxidized CV chondrites come from distinct parent bodies, while CVoxA and CVoxB likely share one. In their words, CVoxA chondrites represent "deeper, more metamorphosed levels than CVOxB chondrites." They proposed treating CVox and CVred as two separate groups rather than subgroups, and showed that the two can be told apart by the average nickel content of their sulfides, the method used for NWA 18497. That proposal is the authors' own; the Bulletin continues to record the subgroup within the CV group.

Frequently asked questions

Has this stone been cut or polished?

No. It is a complete individual with no saw cuts and no polished face. Every surface shown in the photographs is natural exterior.

Does the stone have fusion crust?

Yes. Remnants of fusion crust, the glassy skin formed as the meteorite passed through the atmosphere, remain on parts of the exterior. The stone is not coated.

What does CVox3 mean?

CV is the carbonaceous chondrite group, named for the Vigarano meteorite. "ox" marks the oxidized subgroup, assigned for NWA 18497 on the nickel content of its sulfides and metal. "3" is the petrologic type, indicating the least thermally altered chondrites. The Bulletin writeup further assigns it to the CVoxA branch, following Gattacceca and colleagues (2020).

Is the 725 gram figure the weight of this stone?

No. 725 grams is the recorded mass for the meteorite as a whole, which the Bulletin lists as many pieces. This stone weighs 20.50 grams.

Has NWA 18497 been published?

The entry was approved on 27 March 2026 and is listed for Meteoritical Bulletin 115, which is in preparation. The classification is official; the volume is not yet published.

Who is the seller?

Treasure Coast Meteorite Co., IMCA Member #3323, Hobe Sound, Florida. Background on the Bulletin and what its entries record is in understanding the Meteoritical Bulletin.

Collector significance

This is a whole, uncut individual of an officially classified CV3 chondrite, with fusion crust remnants and chondrules visible on its natural exterior, at a size suited to a display case or study collection.

As of November 2026, the Meteoritical Bulletin lists this as 1 of 67 approved meteorites classified as CVox3.

This specimen is offered by Treasure Coast Meteorite Co., IMCA Member #3323. Browse more carbonaceous chondrites, chondrites and stony meteorites in the collection.

Classification and provenance for this specimen follow the official Meteoritical Bulletin entry for NWA 18497, viewable at the Meteoritical Bulletin Database.