Stone is the most durable and timeless of materials that has been used for thousands of years.
Building stone, also called dimension stone, derives from one of three naturally occurring rock types: igneous (e.g granite), sedimentary (e.g. sandstone and limestone) and metamorphic (e.g marble and slate). Granite, sandstone and limestone can all be used for building walls, but slate is only suitable for roofs and floors. Some types of granite can contain mineral salts that cause spalling, where the outer face of stone falls off; slate can contain harmful minerals that break down on exposure to the atmosphere causing stone damage; and sandstone can be too porous and fragile for load-bearing structures.
An understanding of how the rock material was formed will reveal how it can be used in a building, what its limitations are, and how it will weather over time. Dry stacking or dry stone construction does not require any special tools, only skill in choosing and positioning the stones to create walls, bridges and buildings. However, buying stones from a salvage yard or supplier is not cheap, and it makes sense to only build dry-stone walls if you have plenty of stones on your land. South facing walls and a water butt act as secondary heat sinks, and stones can be incorporated into herb spiral designs and stone hedges.