Why is mica said to have a perfect cleavage?
As Mica splits perfectly parallel to its base, it is considered to have perfect basal cleavage. No other cleavage planes are present in Mica so the flaking occurs readily along this single plane. A good analogy would be a stack of A4 paper. The layers are easily peelable in one direction [parallel to the base] as opposed to the other axis [refer to the miller indices].
