"Pyroxene"-Ilmenite xenoliths from the stockdale pipe, kansas: Chemistry, crystallography, and origin

Abstract

Comparison of serpentine-ilmenite xenoliths from the Stockdale kimberlite pipe, Kansas, with pyroxene-ilmenite xenoliths from African kimberlite pipes indicates both physical and chemical similarity. The intergrown phases are largely single crystals with the ilmenite plates parallel to the crystallographic basal plane of ilmenite. Orthopyroxene and clinopyroxene are oriented such that the b crystallographic axes are parallel to h0h̄0 of ilmenite. The results of textural and crystallographic studies do not definitively answer whether these intergrowths have formed by eutectic crystallization, discontinuous precipitation or eutectoid transformation. © 1975.