UPCAT Earth Science Practice Test 2026 – The Complete All-in-One Guide to Achieve Exam Success!

The property that describes how a mineral breaks along certain planes is called cleavage. Cleavage occurs when a mineral breaks in specific, predictable patterns due to its internal atomic structure. This means that minerals with good cleavage will break along flat surfaces that correspond to the arrangement of atoms in the crystal lattice, resulting in smooth, planar surfaces.

In contrast, fracture refers to the way a mineral breaks in an irregular manner, often resulting in rough and uneven surfaces, without any specific directional preference. Hardness measures a mineral's resistance to scratching, which is unrelated to the way it breaks. Tenacity describes a mineral's toughness or its resistance to breaking or deforming, rather than focusing on the patterns of breakage related to cleavage. Thus, the most accurate term for how minerals break along specific planes is indeed cleavage.