Not all minerals cleave easily. Some fracture instead. Unlike cleavages, which are usually clean, flat breaks, fractures can be smoothly curved, irregular, jagged or splintery.
The most common types of fracture are conchoidal (quartz) , fibrous or splintery, hackly (copper), uneven or irregular.
The sample of malachite shown here has a conchoidal fracture; it's smooth and curved.