NWA 18591 diogenite 43.13 g end cut on a clear stand showing the polished cut face of dark orthopyroxene clasts in an orange-brown weathered matrix, with a scale cube engraved with the Treasure Coast Meteorite Co. logo

NWA 18591 Diogenite Meteorite, 43.13g End Cut, HED Achondrite, Olivine-Bearing from Vesta

$787.00 USD
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NWA 18591 diogenite 43.13 g end cut on a clear stand showing the polished cut face of dark orthopyroxene clasts in an orange-brown weathered matrix, with a scale cube engraved with the Treasure Coast Meteorite Co. logo
  • NWA 18591 diogenite 43.13 g end cut on a clear stand showing the polished cut face of dark orthopyroxene clasts in an orange-brown weathered matrix, with a scale cube engraved with the Treasure Coast Meteorite Co. logo
  • Polished cut face of the NWA 18591 diogenite 43.13 g end cut, a breccia of dark green to black orthopyroxene clasts in a fragmental matrix with orange-brown weathering
  • Close view of the NWA 18591 diogenite end cut face showing large dark orthopyroxene clasts with fine fracture networks set in a tan and orange-brown matrix
  • Macro of the NWA 18591 diogenite end cut face with angular dark orthopyroxene clasts of varying size in a fine tan fragmental matrix
  • Angled close view along the edge of the NWA 18591 diogenite end cut face, showing dark orthopyroxene clasts and rust-brown weathering near the rim
  • Natural weathered exterior of the NWA 18591 diogenite 43.13 g end cut on a clear stand, rough brown surface with dark pyroxene showing through, with a scale cube engraved with the Treasure Coast Meteorite Co. logo
  • Macro of the weathered exterior surface of the NWA 18591 diogenite end cut, brown and rust-toned with dark pyroxene grains and pale weathering deposits
  • Close view of the weathered exterior of the NWA 18591 diogenite end cut, with a dark gray pyroxene-rich patch surrounded by pale and rust-brown weathering
  • Side profile of the NWA 18591 diogenite 43.13 g end cut showing the flat cut face on one side and the domed, weathered natural exterior on the other
  • NWA 18591 diogenite 43.13 g end cut on a clear stand showing the polished cut face of dark orthopyroxene clasts in an orange-brown weathered matrix, with a scale cube engraved with the Treasure Coast Meteorite Co. logo
  • Polished cut face of the NWA 18591 diogenite 43.13 g end cut, a breccia of dark green to black orthopyroxene clasts in a fragmental matrix with orange-brown weathering
  • Close view of the NWA 18591 diogenite end cut face showing large dark orthopyroxene clasts with fine fracture networks set in a tan and orange-brown matrix
  • Macro of the NWA 18591 diogenite end cut face with angular dark orthopyroxene clasts of varying size in a fine tan fragmental matrix
  • Angled close view along the edge of the NWA 18591 diogenite end cut face, showing dark orthopyroxene clasts and rust-brown weathering near the rim
  • Natural weathered exterior of the NWA 18591 diogenite 43.13 g end cut on a clear stand, rough brown surface with dark pyroxene showing through, with a scale cube engraved with the Treasure Coast Meteorite Co. logo
  • Macro of the weathered exterior surface of the NWA 18591 diogenite end cut, brown and rust-toned with dark pyroxene grains and pale weathering deposits
  • Close view of the weathered exterior of the NWA 18591 diogenite end cut, with a dark gray pyroxene-rich patch surrounded by pale and rust-brown weathering
  • Side profile of the NWA 18591 diogenite 43.13 g end cut showing the flat cut face on one side and the domed, weathered natural exterior on the other
NWA 18591 Diogenite Meteorite, 43.13g End Cut, HED Achondrite, Olivine-Bearing from Vesta

NWA 18591 Diogenite Meteorite, 43.13g End Cut, HED Achondrite, Olivine-Bearing from Vesta

Meteorite Details

Meteorite Name: NWA 18591
Subtype: Stony
Classification: Diogenite
Weight: 43.13 g
Year Found: 2024
Fall / Find: Find
Location: Northwest Africa
IMCA Member #3323 Treasure Coast Meteorite Co.
$787.00 USD

A 43.13 gram olivine-bearing diogenite end cut from asteroid Vesta

This is a 43.13 g end cut of NWA 18591, a diogenite classified as an olivine-bearing HED achondrite from asteroid 4 Vesta. Diogenites formed deep in Vesta's crust, where minerals settled out of slowly cooling magma, so they are coarser and more orthopyroxene-rich than the basaltic eucrites from the surface. The polished cut face shows the brecciated interior of the meteorite: dark orthopyroxene clasts set in a fragmental matrix, with the tan tones of moderate desert weathering across the surface. For background on the type, see our guide on what an achondrite is.

Structure and features of this end cut

The polished cut face reveals a breccia built from millimeter to centimeter sized clasts of orthopyroxene set within a finer fragmental matrix, the record of impact processing on Vesta's surface. Under close light the pyroxene clasts read as dark green to near black, threaded with fine fracture networks, while the surrounding matrix carries the orange and tan coloring of moderate terrestrial weathering. Scattered olivine accompanies the orthopyroxene, which is why the meteorite carries the olivine-bearing designation, and accessory chromite, iron metal, and troilite are present in the rock. As an end cut, the piece keeps the outer surface of the stone on its back side: a rough, brown weathered exterior with dark pyroxene showing through and patches of pale weathering deposits, which shows how the meteorite looked before it was cut. It is photographed alongside a one centimeter scale cube.

Discovery and provenance

NWA 18591 was found in northwest Africa in 2024 as seven stones with weathered fusion crust, for a total known weight of approximately 610 grams. The stones were acquired from a dealer in Morocco, and the main mass is held by Treasure Coast Meteorite Co. The meteorite was classified by D. Sheikh at the Cascadia Meteorite Laboratory at Portland State University, where a 22.8 gram type specimen is on deposit, and the name was approved by the Meteoritical Society in 2026. This end cut therefore comes directly from the holder of the main mass, with provenance that traces to the classifying laboratory. Browse related specimens in our Diogenites collection.

Scientific context

Diogenites are orthopyroxenite achondrites from the deep crust of asteroid 4 Vesta, part of the howardite, eucrite, and diogenite family whose common origin is confirmed by oxygen isotopes, pyroxene chemistry, and the reflectance spectra measured directly at Vesta by NASA's Dawn mission. In NWA 18591 the low-calcium pyroxene has a ferrosilite content of Fs27.8 with a magnesium number of about 72, and the accompanying olivine sits at Fa27.0, values consistent with an olivine-bearing diogenite. The rock records a moderate shock stage, evidence of the impact history that brecciated Vesta's crust and eventually launched this material toward Earth. The classification is published in the Meteoritical Bulletin, No. 115. You can read more about how meteorites earn an official record on our Meteoritical Bulletin explained page.

Frequently asked questions

Is this meteorite authenticated?
Yes. NWA 18591 is an officially classified diogenite recorded in the Meteoritical Bulletin, No. 115, with its main mass held by Treasure Coast Meteorite Co. This end cut ships with a Treasure Coast Meteorite Co. certificate of authenticity and is offered by Treasure Coast Meteorite Co., IMCA member #3323.

What is a diogenite?
A diogenite is an orthopyroxene-rich achondrite from the deep crust of asteroid 4 Vesta, coarser grained than the basaltic eucrites that formed at the surface of the same body. Learn more on our Diogenites collection page.

What does olivine-bearing mean here?
The classification notes that this diogenite contains olivine alongside its dominant orthopyroxene. Olivine-bearing diogenites sample slightly different levels of Vesta's cumulate pile than orthopyroxene-only diogenites.

What is an end cut?
An end cut is the piece left at the end of a stone after slicing. It has one flat polished cut face showing the interior and keeps the original weathered exterior on the other side, so you can see both the inside and the outside of the meteorite in one specimen.

What is included?
The 43.13 g end cut shown, with a Treasure Coast Meteorite Co. certificate of authenticity.

Collector significance

An end cut of a classified diogenite whose main mass is held in house is a strong provenance piece, tying the specimen directly to the meteorite's holder and to the Cascadia Meteorite Laboratory that classified it. The brecciated orthopyroxene texture and the olivine-bearing chemistry make this a representative sample of Vesta's deep crust, a good anchor for an HED suite alongside eucrites and howardites. Full classification data, chemistry, and provenance are published in the Meteoritical Bulletin entry for NWA 18591.

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