How does crystal structure determine mineral cleavage?

1 Answer
Sep 17, 2015

every crystal structure has a definite shape like
cubic ,hexagonal ,FCC etc

A plane named cleavage plane is present in every crystal system

So due to the particular type of crystal plane the mineral which has the crystal system cleaves only in a particular direction

#In# # cubic# # system#
the cleavage occurs in {001} planes

In #hexagonal#(basal clevage) and #Rhombhohedral# clevage occurs in {0001} planes
in FCC cleavage occurs in [111] plane
Diamond which has Octahedral cubic has Octahedral clevage

for planes of hexagonal system refer (Miller-Bravias Indices for Hexagonal crystal sytsem )