Summary: Chrome spinels from seams in the Rhum layered intrusion, Inner Hebrides, generally contain very fine platelets of exsolved phases. Despite the low bulk Ti content (< 1%) of the spinel grains, analytical electron microscopy shows these platelets to be highly enriched in titanium. Electron diffraction indicates the presence of platelets of two different phases, one a magnesian ilmenite, the other a defect spinel intermediate phase. The platelets are the result of oxidation of the spinel at moderate (c. 600 °C) temperatures and their distribution suggests that oxygen fugacity gradients existed across some of the seams.
Mineralogical Magazine; December 1979 v. 43; no. 328; p. 519-526; DOI: 10.1180/minmag.1979.043.328.12
© 1979, The Mineralogical Society
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