Answer:
A. a mineral can only break in one way
Explanation:
Cleavage is the ability of crystals to break along preferred crystallographic directions with the formation of a glossy surface. In the characterization of minerals the cleavages are described as:
• perfect cleavage: crystal separates into perfect surface plates (eg micas)
• good cleavage: separation takes place in certain directions, often forming stepped surfaces (eg calcite, cyanite)
• distinct cleavage: when the formation of equal and uneven surfaces by breaking occurs (eg feldspars, hornblende)
• imperfect cleavage: cleavage surfaces are uneven (eg beryl)
• missing cleavage: no cleavage plan (eg quartz)
Minerals may have cleavage surfaces on:
a) 3 directions - eg calcite, galena
b) 2 directions - Ex .: feldspar
c) 1 direction - Ex .: micas, talc
d) absent - eg quartz, tourmaline
