Having unequal oblique axes as anorthic crystals
- having three unequal crystal axes intersecting at oblique perspectives
- Having unequal oblique axes; since, anorthic crystals.
(a.) Having unequal oblique axes; because, anorthic crystals.
Dark coloured micas are strongly pleochroic. Accurate determinations of the optical orientation, as well as the symmetry of the etching figures on the cleavage planes, seem to suggest that the micas, except muscovite, may be anorthic rather than monoclinic in crystallization.