Ramdohr considers the possibility of a polishing effect, and observes also
a differential etching with HF and a noticeable magnetism. I should
suggest to etch and to analyse both phases under the SEM/EMP.
Two possibilities could be considered, if chemical differences are not obvious:
-two hematite phases with slightly different V-, Ti- or Cr-,...contents,
-intergrowth of hematite/maghemite (which have both the same chemical
composition), but different reflectivities and ferromagnetism.
J.J.
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