Zag is a witnessed H3-6 Ordinary Chondrite fall from the Morocco and Western Sahara border region, which fell on 4 or 5 August 1998. The fall was reportedly seen on a mountain near Zag, and around 175 kg of material was later sold under the names Zag, Sagd, and Tan-Tan. As an H Chondrite, Zag contains relatively high iron compared with L and LL Chondrites, while its H3-6 classification indicates a brecciated mixture of material ranging from primitive type 3 to more thermally altered type 6 components.

Zag specimens typically show the mixed texture of a regolith breccia, with chondrules, metal grains, clasts, and material altered to different degrees on the parent asteroid. The type 3 portions preserve more primitive Chondritic features, while the type 6 material records stronger thermal metamorphism. Zag is also scientifically notable for containing halite crystals and trapped water, an unusual feature that has added to its research interest beyond its classification as an Ordinary Chondrite.

Studying Zag provides valuable insight into regolith development, impact mixing, and the preservation of volatile-bearing minerals within Ordinary Chondrite parent bodies. Its witnessed fall status, substantial recovered mass, unusual halite-bearing material, and recognised H3-6 classification make it especially desirable for collectors of Chondrites, witnessed falls, and scientifically distinctive meteorites. Each specimen represents ancient asteroid material connected to a clearly documented event in 1998.