Types of stone

[edit] Introduction

Stone, or rock, is a natural substance that is quarried and mined from the earth and used in a variety of applications in construction, including:

• Masonry.
• Flooring coverings.
• Paving.
• Roof coverings.
• Aggregate.
• Ballast.
• Fire surrounds and other decorative elements.
• A component of concrete, mortar, cement, asphalt and some bricks.

The major rock groups are igneous, sedimentary and metamorphic. The unique characteristics of stone are due to the complex geological processes that have impacted upon it, creating many different types of structure, texture and colour.

Some of the different types of stone include:

[edit] Basalt

Basalt is an igneous rock that is formed from molten rock that has solidified under pressure. It has a uniform grey colour and is very hard and compact.

[edit] Granite

Granite is an igneous rock composed of quartz, mica and feldspar. It is very hard which makes it suitable for applications that will require wear resistance. It can range in colour from light grey to black, pink and green, according to the mineral content.

[edit] Limestone

Limestone consists of calcium carbonate formed at the bottom of shallow lakes and seas that has been compacted over time. It can be categorised as either soft or hard limestone. Various colours can be found as a result of the presence of different minerals in the limestone.

[edit] Marble

Marble is a metamorphic rock that is predominantly composed of calcite or dolomite crystals. It is characterised by its crystal-like texture which is formed by limestone being changed by a combination of heat and pressure. It is both hard and compact, and is often used for decorative purposes in interior design.

[edit] Sandstone

Sandstone is composed of quartz particles that have eroded from other rocks, commonly granite, and cohered together with natural cement minerals in groundwater before being compacted.

[edit] Quartzite

Quartzite is a metamorphic rock which is formed from pure quartz sandstone as a result of heating and pressure. Quartzite is hard and angular, commonly used for railway ballast, as well as for tiles and flooring.

[edit] Slate

Slate is a fine-grained metamorphic rock that is formed when sedimentary rock such as shale is subject to high pressure. Slate is strong and has very good weather resistance as well as low water absorption, meaning that it withstands freezing temperatures well. It is most commonly used as a roof covering.

[edit] Travertine

Travertine is a type of limestone that is formed by rapid precipitation of calcium carbonate, most commonly at the mouth of a hot spring. It is characterised by pitted holes and troughs in its surface, although these are often polished to a smooth finish. It is a popular stone for use in facades, wall cladding and flooring.

[edit] Find out more

[edit] Related articles on Designing Buildings Wiki

• Defects in stonework.
• Masonry.
• Natural stone.
• Natural stone cladding.
• Natural stone tiles.
• Patio stone.
• Roof slates.
• Stone dressing.
• Types of brick.
• Types of concrete.