Fracture in minerals is characterized by which description?

• A. Breaks along smooth planes
• B. Breaks irregularly with no well-defined planes
• C. Occurs only in igneous rocks
• D. Is the same as cleavage

Answer: (B)

The key idea is how a mineral breaks when there aren’t clear planes of weakness. When a mineral lacks distinct cleavage planes, it tends to fracture irregularly, producing surfaces that don’t line up into smooth, flat faces. That’s why the correct description is that it breaks irregularly with no well-defined planes. Cleavage, by contrast, is a tendency to break along smooth, flat planes that follow the crystal lattice, so it’s not the same as fracture. Fracture isn’t limited to any rock type, so it’s not correct to say it occurs only in igneous rocks. Minerals like quartz show irregular or conchoidal fracture, illustrating how fracture differs from cleavage.