Cleavage

 

1 The tendecy of a crystalline mineral to break in certain definite directions, parrallel to a possible crystal face, leaving a more or less smooth surface.

2 Any break along the grain of a diamond parrallel to one or four pairs of octahedral faces.

3 The act or process of producing such a break.

5 A term sometimes used for a diamond crystal that requires cleaving before being fashioned.