If a mineral lacks planes along which it may cleave, which physical property does it most likely exhibit instead?

• A. Luster
• B. Hardness
• C. Fracture
• D. Streak

Answer: (C)

Verified step by step guidance

1. Understand the concept of cleavage in minerals: Cleavage refers to the tendency of a mineral to break along specific planes of weakness in its crystal structure, resulting in smooth, flat surfaces.
2. Recognize that if a mineral lacks these planes of weakness, it cannot cleave, so it will break in a different manner.
3. Learn that when a mineral breaks without cleavage planes, it exhibits a property called fracture, which describes an irregular or uneven breakage surface.
4. Differentiate fracture from other physical properties listed: Luster describes how light reflects from a mineral's surface, hardness measures resistance to scratching, and streak is the color of the mineral's powder.
5. Conclude that the physical property most likely exhibited by a mineral lacking cleavage planes is fracture.