Types of Natural Stone for Home Decoration

In our time, stone houses have given way to cheaper (more practical, more eco-friendly, and so on) alternatives, but stone itself, firmly associated with strength, wealth, and reliability, has kept its place in country construction. Only its role has changed: it has become a favorite finishing material.

Scientists recognize about 9,000 kinds of natural stone, but not all of them are suitable for "construction" purposes. There are many reasons for this, and to spare you a lot of unnecessary questions, today we propose getting acquainted with the rocks most commonly used in the finishing trade.

Granite

A natural stone complex in composition and an indispensable building and finishing material: durable, hard, and wear-resistant, thanks to the quartz it contains. It has a pronounced grainy, crystalline structure, and by grain size it is classified as fine-, medium-, or coarse-grained.

Physical properties: durable and strong; takes a good polish and keeps its mirror shine for a long time; easy to grind, so a variety of textures can be achieved; has high wear resistance and low water absorption; does not lose its decorative qualities under any conditions of use.

Color palette: gray in various shades (the most common), pink, red, orange, bluish-gray, and bluish-green (amazonite); occasionally a stone with blue quartz.

Disadvantages: a rough surface, and rapid cracking and spalling in a fire.

Applications of granite:

• cladding of plinths and facades
• floor and wall lining inside buildings
• manufacture of steps of all kinds
• paving of squares and paths
• small architectural forms, including fountains
• as crushed stone in civil engineering

Syenite (Egyptian granite)

A plutonic rock, similar in appearance to granite but distinguished by its less pronounced granularity and the absence of quartz (which makes syenite easier to work). It is used in construction in the same way as granite.

Color palette: usually darker than granite; it can be gray, gray-blue, pink, or pinkish-gray. The color depends on the presence of dark-colored minerals (pyroxene, hornblende, and others).

Physical properties: syenites have high resistance to pressure and loads, tolerate temperature swings well, are fire-resistant, have a low water-absorption coefficient, and take a good polish. Density: 2,600-2,800 kg/m2. Strength: 150-300 MPa.

Disadvantage: not especially resistant to weathering.

Applications of syenite:

• cladding of plinths and facades, and of floors and walls inside buildings
• manufacture of steps of all kinds
• paving of sites and paths
• small architectural forms, including fountains
• roofing material

Gabbro

A deep-seated (igneous) crystalline rock, usually coarse- to medium-grained; it has the same structure and applications as granite.

Color range: dark grayish-green to black; the green varieties are called olivine gabbro.

It is easy to machine, polishes very well, and keeps its luster for a long time; when polished it takes on great depth, which sets it apart from other black stones. It is highly durable, withstands frost well, and is highly resistant to weathering.

Disadvantage: in high-traffic areas, gabbro floors quickly lose their polish.

Applications of gabbro:

• facade cladding and exterior finishing of buildings
• floor cladding in private houses
• monumental art and monuments

Labradorite (peacock stone)

A magmatic, crystalline-grained rock.

Color palette: usually black and gray, occasionally light. Iridescent surface patches of blue-green, and more rarely golden-yellow or orange, give the stone its decorative effect.

Physical properties: high strength, wear resistance, and frost resistance; water absorption no more than 0.21; density 2.71; the stone is moderately hard, brittle, takes an excellent polish, and is extremely decorative.

Applications of labradorite:

• exterior finishing of buildings
• floors, columns, and wall plinths
• monumental architecture

Porphyry

A general term for rocks with a porphyritic structure: an unevenly grained structure in which large crystals set in the groundmass (usually volcanic glass) are mixed with minerals (porphyritic segregations). In chemical composition and properties, porphyries are close to granite. Porphyry takes its name from the distinctive red rock with large white orthoclase crystals (a variety of feldspar), which has been used since ancient Rome for luxury objects and statues of the Caesars.

Color palette: dark red, purple porphyry is extremely decorative and was used in monumental art; you can also find gray, yellow, pink, and brown in various shades.

Physical properties: hard, very decorative, resistant to crazing, and long-lasting; easy to polish; has a low water-absorption coefficient. Its individual characteristics depend on the composition of the stone.

Applications of porphyry:

• cladding of floors, columns, and wall plinths
• monumental architecture
• paving of terraces, sidewalks, paths, and driveways

Quartzite

A fine-grained sedimentary rock formed by the alteration of siliceous sandstones. Known since ancient times, it can be seen in the decoration of the Church of the Savior on Spilled Blood and the upper part of the Lenin Mausoleum.

Color palette: gray, pink, and yellow; the most decorative are crimson-red and dark cherry, and there is sometimes white quartzite. The color is determined by the presence of iron pigment.

Physical properties: it is very hard, yet can be polished to a very high quality, which makes it a highly decorative finishing material. It is extremely durable, acid-resistant, and frost-resistant, with a compressive strength of 100-450 MPa, a low water-absorption coefficient, and a density of about 2.7 g/cm³.

Applications of quartzite:

• monumental construction
• facade and basement cladding
• interior finishing
• paving of terraces, platforms, and retaining walls

Marble

A metamorphic rock formed under high temperature and pressure and consisting solely of calcite. In construction, the name "marble" is applied not only to this stone but also to other similar rocks, such as marble-like limestones, dolomites, and carbonate breccias.

Color palette: "pure" marble is usually a light, uniform color, such as white, grayish, or yellowish. In other marbles, impurities of other minerals (hematite, limonite, manganese oxides, graphite, and so on) give shades of green, red, and even black.

Marble often has a pattern: mottled, spotty, wavy, or moire. Polishing brings out the pattern and color; honing reduces their brightness and clarity; a riven texture hides the pattern and lightens the overall background.

Physical properties: easy to machine, easy to polish, and extremely decorative; medium hardness; density about 2.7; a good dielectric; good heat-resistance ratings.

Disadvantage: the most valuable fine-grained white marble, famous for its warm tone and "translucent" structure, is very capricious, as it is prone to staining and yellowing in unfavorable conditions.

Applications of marble:

• laying of interior floors
• cladding of walls, stair flights, fireplaces, and saunas
• production of balusters
• creation of sculptures, mosaic compositions, and bas-reliefs

Slate

A layered, fine-grained stone formed from clays, sedimentary rocks, and sometimes quartz. A characteristic feature is its ability to split into thin plates. It is quite a popular cladding stone today.

Color palette: dark gray, black, gray-brown, yellow, and red-brown, often mottled.

Physical properties: the properties common to all types of slate are a strong structure, sufficient water resistance (water absorption of 0.1-3%), frost and fire resistance, and excellent heat and sound insulation. It is easy to work, cuts well without crumbling, and resists the effects of the environment. Hardness, water absorption, color, and texture depend on the type of stone, as slate is very heterogeneous. Only black, green, and gray slate can be polished; slate tiles are usually left with a natural, slightly uneven surface, and less often polished.

Applications of slate:

• exterior and interior wall and floor cladding
• cladding of fireplaces and stairs, demarcation of separate zones, and decoration of arches, niches, and so on
• landscape compositions; paving and landscaping around outbuildings
• as a roofing material

Travertine

Calcareous tufa, an intermediate form of stone between limestone and marble. An ideal material for tilework.

Color palette: the most common shades range from light beige to hazelnut; darker, brownish shades of travertine are less common; there are also intensely colored travertines, red and yellow, from Iran.

Physical properties: a low abrasion coefficient, high thermal conductivity and heat resistance, and light weight; it cuts, grinds, and polishes well, and it does not become slippery when wet. The properties of travertine depend on the conditions under which the stone formed: the more organic inclusions it contains (shells, leaves, and so on), the more porous it will be; its density is determined by the depth at which it formed. A peculiarity of travertine is its ability to change after quarrying; pale varieties may turn yellow because of the oxidation of iron salts, while their hardness increases over time.

Darker travertine varieties have better technical qualities. White travertine is usually left unpolished: its warm color compares favorably with the cool white of polished marble.

Applications of travertine:

• exterior wall cladding
• floor paving
• cladding of fireplace surrounds and stairs, demarcation of zones, decoration of arches, niches, and so on
• decoration of bathrooms and saunas

Dolomite

A sedimentary rock consisting of the mineral of the same name; a "relative" of marble.

Color palette: colorless or white, yellowish, or brownish (due to admixtures of iron hydroxides and clay particles); its luster ranges from glassy to matte and pearly; it often has a fanciful pattern. Valuable pink dolomites are rare, as are translucent and transparent ones.

Physical properties: durability, frost resistance, high strength, and refractoriness; easy to work; the hard grades can be polished.

Structurally, dolomites can be marble-like, porous, or dense. The dense ones are used to make cladding slabs for the exterior finishing of buildings. These are the famous Balakovo, Kovrov, and Kokcheyevo dolomites, which Russian architects have used since the earliest times to build white-stone churches. The porous varieties are used in garden design.

Applications:

• interior and exterior finishing
• landscape design (dry walls, retaining walls)
• paving of paths and squares

Breccia

A clastic rock consisting of fragments of one (monomictic) or several (polymictic) rocks bound together by some mineral substance (cement). It differs from conglomerates (cemented rounded pebbles) in the angular shape of its included pebbles and rubble, and in its origin.

Physical properties: average density in the range of 2,600-2,850 kg/m3; compressive strength of 50-160 MPa. The presence of inclusions of differing hardness makes the stone difficult to cut and grind. Breccias polish unevenly, because the cementing agent does not take a polish.

Color palette: the popular varieties are variegated red, brown, gray, black, green, and yellow, but there are also relatively monochromatic brown-yellow or red-brown varieties. The variety of inclusions makes breccia a very decorative stone.

Applications:

• flooring
• interior wall cladding (polished slabs only)
• paving of paths and squares

Sandstone

A sedimentary rock; a homogeneous or layered aggregate of sand grains bound together by a mineral (cement). The strength of the material depends on this binder: the strongest are siliceous sandstones, while if the binder is easily soluble (gypsum or clay), the sandstone is short-lived.

In construction and finishing, quartz sandstones are used, as well as arkose (with a predominance of feldspars) and graywacke (sandstones of complex composition with a high percentage of rock fragments).

The color palette is gray, gray-green, shades of yellow, red-brown, and brown. Fine-grained red, brown, and green varieties of sandstone are considered ornamental. Physical properties: density (2,250-2,670 kg/m3), durability, and high wear resistance; water absorption 0.63-6.0%; porosity depends on the composition of the stone and ranges from 0.69 to 6.70%.

Sandstones do not lend themselves to polishing, so the most popular sandstone textures are riven, sawn, and sometimes honed. By degree of processing, sandstones are divided into three groups:

• sawn sandstone — a solid rock sawn into layers;
• riven sandstone — irregularly shaped natural slabs, varying in size and thickness;
• rubble sandstone — rough-shaped stones obtained by blasting, used for landscaping and for laying building foundations.

Applications:

• cladding of plinths and walls of houses, fences, and columns
• cladding of interiors (fireplaces in particular) and stairs
• laying of footpaths, garden paths, and terraces
• landscape design (fountains, streams, cascades, rock gardens)

Limestone

A sedimentary rock, usually of organic origin, consisting mainly of calcite, often with an admixture of quartz, clay, and sandy particles; it often contains the remains of fossil skeletons.

The physical properties of the material are determined by its composition and structure.

By structure, limestones are divided into:

• dense — made of fine-grained calcite and fragments of lime shells; this limestone is used to make slabs for exterior and interior cladding;
• porous — calcareous tufa, travertine, and all kinds of decorative coquina;
• marble-like;
• earthy (chalk).

By compressive strength, limestones, like dolomites, are conditionally divided into three groups: strong, medium-strength, and low-strength.

• Strong (marble-like) limestones take a good polish, give a mirror shine, and are used for exterior and interior finishing and for flooring.
• Medium-strength ones give a glossy surface — a soft, non-mirror sheen. They are suitable for stone cladding and flooring in private homes and apartments.
• Low-strength ones do not take a polish; only honing is possible. They are not recommended for flooring, but they are good for stone carving, small architectural forms, and vertical stone veneers.

Limestone has good frost resistance (40 to 100 cycles), is easy to machine, and, when polished, is very decorative.

Color palette: most often white, yellowish, or light gray, and less often pinkish. In terms of decorative value, white limestone with a yellow or pink hue is considered the most prized; black limestone is known as anthraconite.

Applications:

• interior and exterior cladding of buildings and premises
• retaining walls in landscaping, in the form of stone masonry