Errachidia 004 is a rare Primitive Achondrite from Morocco, classified as a Winonaite and found in 2020 near the rural community of Oued Naam in the Errachidia region. Winonaites are transitional meteorites, showing evidence of partial melting while still retaining links to primitive asteroid material. Errachidia 004 is especially interesting because it contains distinct low-metal and high-metal lithologies, reflecting a complex history of heating, mixing, and impact processing.

Specimens of Errachidia 004 can vary noticeably in appearance. Many fragments show low visible metal and lack clear chondrules, while others contain much higher amounts of iron-nickel metal, sometimes with a well-developed Widmanstätten pattern. This dual-lithology nature gives the meteorite unusual visual and scientific character, with prepared pieces ranging from stony, fine-grained material to metal-rich sections with strong contrast.

For collectors, Errachidia 004 offers a scarce opportunity to acquire a recognised Winonaite with an unusually varied internal structure. Its limited recovered mass, Moroccan provenance, and anomalous characteristics make it particularly appealing for collections focused on Primitive Achondrites, transitional meteorites, or unusual parent body material. Each specimen represents part of a complex early solar system body that experienced partial differentiation without fully separating into a typical core and mantle structure.