Aletai meteorite spheres are made from the Aletai iron meteorite, which was discovered in 1898 in the Altay region of Xinjiang in northwest China. Classified as a coarse octahedrite, this meteorite formed more than 4.5 billion years ago within the metallic core of a large asteroid. When the spheres are polished and etched, the Widmanstätten pattern becomes visible, revealing the natural nickel-iron crystal structure created by extremely slow cooling in space.
Each sphere shows a distinctive arrangement of metallic crystal bands across its surface. These structures formed as the asteroid gradually cooled over immense periods of time. Because the pattern cannot be reproduced artificially, Aletai meteorite spheres are widely collected as genuine extraterrestrial specimens.