Types of Building Stone

Building stone as know as dimension stone which is derives from one of three naturally occurring rock types:

    1.   Igneous stone

• Hard and non-porous rock formed either the slow or quick cooling of molten magma.
• Example: Granite à used for building wall.

                                    à Some types of granite consist of mineral salts which cause spalling where the surface of stone falls off

Igneous stone

Granite

    

2.   Sedimentary stones

• Soft and fairly porous rock formed from deposits of eroded pre-existing rock that settled in layers. Mostly on sea beds and became compacted.
• Example: - Sandstone à used for wall.

                                       à Too porous and fragile for load-bearing structures.

                               - Limestone à used for wall.

Sedimentary stone

Sandstone

Limestone

3.   Metamorphic stones

• Hard and non-porous rock formed from pre-existing rock that has been altered by intense heat or pressure.
• Example: - Marble

                               - Slate à used for roofs and floors.

                                   à Consists of harmful minerals that break down on exposure to the atmosphere causing stone damage.

Metamorphic stone

Marble

Slate