A PALL�💜�ASITE FROM AN EARLY 20TH CENTURY MEXICAN FIND

As in the case with all pallasites, Ahumada originated from the core-mantle boundary of a differentiated asteroid, which is an asteroid that was once hot enough for melting to occur, allowing denser and less dense materials to segregate into core, mantle, and crust layers. Ahumada was found in 1909 as a single 116 pound (52.6 kg) meteorite in the deserts of Chihuahua, Mexico, about 60 miles east of the town of Ahumada. As o🌸ne of the orig🍌inal cuttings, this slice is quite a bit thicker than most modern pallasite slices: 6 millimeters as opposed to the more common 3 millimeters found today. One side has been etched and polished to bring out the Widmanstätten pattern hidden in the pallasite's iron-nickel matrix, while the other side has maintained its original look after cutting.

Pallasites such as Ahumada are incredibly rare, accounting for .2% — or just 1 out of 500 — of all meteorite ♈finds. The olivine crystals found embedded in Ahumada are the remnants of pieces of an asteroid's stony mantle becoming suspended in the molten metal of its iron-nickel core. The prominent metallic latticework found on the display side of the slice is referred to as a Widmanstätten pattern and is the result of sl🅘ow cooling over millions of years, providing sufficient time for the two iron-nickel alloys present in the meteorite to orient into a crystalline habit. As Widmanstätten patterns can only occur within certain types of asteroids in the vacuum of space, their presence is diagnostic in the identification of a meteorite.

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