Biotite Flakes: Alteration by Chemical and Biological Treatment

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Science  13 Jan 1967:
Vol. 155, Issue 3759, pp. 193-195
DOI: 10.1126/science.155.3759.193


Biotite alteration under acid conditions proceeds differently from the generally accepted pathway of transformation to vermiculite in which hydrated cations cause interlayer expansion, resulting in a dark-colored peripheral band on mica particles. Acid solutions of synthetic or biologic origin remove octahedral ions, leaving a fragile matrix of amorphous material.