When sliced and polished,
pallasites are among the most beautiful of meteorites. These specimens contain
crystals of olivine, the semi-precious stone
peridot, contained within a matrix of nickel-iron very much like the bits of
fruit in a slice of fruitcake. The color of the olivine crystals can vary from
a deep amber to light green depending on the particular meteorite being viewed.
In thin slices of pallasites, the crystals are translucent to light.
Unfortunately, thin slicing is a poor method of preparing pallasites as the
crystals have little metal to hold them in the matrix.
Pallasites are very scarce and
believed to have formed on differentiated bodies in the transition area between
the metal-rich core and the olivine-rich mantle where the olivine could cool
slowly enough to form relatively large crystals. The Brenham pallasite is a
representative and relatively available example of this class.
New England Meteoritical