Stone behavior under load: the natural tendency of a stone is to split along which feature of its internal makeup? Choose the most accurate term used in stone technology.

Introduction / Context:
Quarrying, dressing, and using stone blocks require understanding the preferred planes along which stone tends to split. Selecting the correct orientation improves strength and durability of masonry and facing slabs.

Given Data / Assumptions:

• Terms like texture, fracture, cleavage, and structure have specific meanings in geology/materials.
• We focus on the natural planes of easy separation.

Concept / Approach:

“Cleavage” denotes the propensity of a crystalline or layered rock to split along specific planar surfaces of weakness. This is distinct from “texture” (grain size/arrangement), “fracture” (irregular breakage when no cleavage planes are available), and “structure” (larger-scale features like bedding or foliation). In practice, stones are often dressed so that loads act normal to planes of cleavage to mitigate splitting risk.

Step-by-Step Solution:

Verification / Alternative check:

Petrography texts define cleavage as a mineral/rock property of splitting along crystallographic planes or preferred orientations, matching quarry observations.

Why Other Options Are Wrong:

Texture: does not specify a splitting plane. Fracture: irregular, not preferential planes. Structure: broad term; may include bedding or joints but not the intrinsic cleavage behavior implied.

Common Pitfalls:

Confusing bedding/foliation with cleavage; while related in layered rocks, the exam term directly targeting splitting tendency is “cleavage”.

Final Answer:

cleavage