What do we call the mineral's resistance to scratching?

The term used to describe a mineral's resistance to scratching is hardness. This property is fundamental in mineral identification and is defined by how well a mineral can withstand physical abrasion or pressure. The Mohs scale of mineral hardness is commonly used for this purpose, ranking minerals from talc, the softest, to diamond, the hardest.

In practical applications, understanding a mineral's hardness helps geologists and miners assess its durability, usefulness in construction materials, and implications for various industrial processes. This property is crucial for determining the suitability of a mineral for tools and other applications requiring durability.

Other terms listed have distinctly different meanings: cleavage refers to the way some minerals break along specific planes, fracture describes how a mineral breaks when it does not have cleavage, and luster is related to the appearance of a mineral's surface in terms of shine or reflection. Each of these properties plays a role in mineral identification, but when specifically discussing scratching resistance, hardness is the correct term.