This property of breaking along specific planes is termed cleavage. Because cleavage occurs along planes in the crystal lattice, it can be described in the same manner that crystal forms are described.

What happens when a mineral breaks along a plane?

When crystals break, they can either split leaving a clean, flat face called a cleavage plane, or fracture leaving a more rough, uneven surface. We can find out more about a crystal by looking at the way it breaks. Cleavage planes form along the weakest area of mineral's structure.

Can minerals break apart in a specific way?

Each kind of mineral always breaks in the same way, and this property can help identify a mineral. In fact, the way a mineral breaks is a better clue to its identity than are its color and luster. Calcite has cleavage.