NATURAL STONESNATURAL STONES

NATURAL STONESNATURAL STONES

Stones are made up of Stones are made up of mineralsminerals in in various mixtures.various mixtures.

Individual samples vary greatly in Individual samples vary greatly in composition.composition.

These variations greatly affect the These variations greatly affect the strength, colour, texture,strength, colour, texture, and and durabilitydurability of stone. of stone.

MINERALSMINERALS Elements which can be described in Elements which can be described in

chemical terms or compounds composed of chemical terms or compounds composed of two or more elements and found naturally in two or more elements and found naturally in the crust of the earth are termed the crust of the earth are termed mineralsminerals..

Nearly all of the rock - forming minerals are Nearly all of the rock - forming minerals are silicatessilicates, that is, they contain one or more , that is, they contain one or more metals in combination with silicon and metals in combination with silicon and oxygen.oxygen.

Some of the rock – forming minerals are Some of the rock – forming minerals are quartz, calcite, gypsum, mica, feldspar, quartz, calcite, gypsum, mica, feldspar, hornblende and augite.hornblende and augite.

Mineral PropertiesMineral Properties Hardness:Hardness: Field tests for hardness are based on the Field tests for hardness are based on the

capability of a mineral to scratch anything capability of a mineral to scratch anything softer than itself. A set of ten minerals with softer than itself. A set of ten minerals with talc as number one (1) (the softest) and talc as number one (1) (the softest) and diomand as number ten (10) (the hardest) is diomand as number ten (10) (the hardest) is referred to as Moh’s scale of hardness.referred to as Moh’s scale of hardness.

Specific Gravity:Specific Gravity: The relative weight of a mineral when The relative weight of a mineral when

compared with the weight of an equal volume compared with the weight of an equal volume of water is the specific gravity (G) of that of water is the specific gravity (G) of that mineral. For example, the specific gravity of mineral. For example, the specific gravity of gypsum is 2.3 (water as 1).gypsum is 2.3 (water as 1).

CLASIFICATION OF CLASIFICATION OF STONESSTONES

IGNEOUS IGNEOUS SEDIMENTARSEDIMENTARYY

METAMORPHIMETAMORPHICC

GRANITEGRANITE

SYENITESYENITE

DIORITEDIORITE

GABBROGABBRO

RHYOLITESRHYOLITES

ANDESITEANDESITE

BASALTBASALT

CONGLOMERACONGLOMERATTEE

SANDSTONESANDSTONE

SHALESHALE

BRECCIABRECCIA

LIMESTONELIMESTONE

TRAVERTINETRAVERTINE

MARBLEMARBLE

SLATE (Arduvaz)SLATE (Arduvaz)

SCHIST (YaprakSCHIST (Yaprak Kayaç, şist)Kayaç, şist)

GNEISSGNEISS

QUARTZITEQUARTZITE

THE ROCK CYCLETHE ROCK CYCLE

IGNEOUS STONESIGNEOUS STONES

Igneous Stones have been formed of Igneous Stones have been formed of material which has been molten by material which has been molten by the intense heat within the interior of the intense heat within the interior of the earth and become solidified.the earth and become solidified.

They are divided into three group:They are divided into three group:

Plutonic RocksPlutonic Rocks

Hypabyssal RocksHypabyssal Rocks

Volcanic RocksVolcanic Rocks

A- A- Plutonic RocksPlutonic Rocks Plutonic RocksPlutonic Rocks are igneous rocks which are igneous rocks which

have been consolidated at a considerable have been consolidated at a considerable depth below the earth’s surfacedepth below the earth’s surface

TThe erosion (wearing away) of the upper he erosion (wearing away) of the upper and softer strata has caused such rocks and softer strata has caused such rocks to appear at the earth’s surface.to appear at the earth’s surface.

Consolidation was gradual owing to the Consolidation was gradual owing to the extremely extremely slow rate of coolingslow rate of cooling, and such , and such rocks are therefore rocks are therefore completely crystalline completely crystalline and have a coarse – grained texture.and have a coarse – grained texture.

These rocks consist of silica in combination These rocks consist of silica in combination with bases such as iron, lime, magnesia, with bases such as iron, lime, magnesia, potash and soda, and potash and soda, and they arethey are classed as classed as acid, intermediate or basic, according to acid, intermediate or basic, according to the percentage of silica content.the percentage of silica content.

Thus, acid rocks have over 66 per cent. of Thus, acid rocks have over 66 per cent. of silica, intermediate rocks have from 52 to silica, intermediate rocks have from 52 to 66 per cent. of silica and the silica content 66 per cent. of silica and the silica content of the basic group is less than 52 per cent.of the basic group is less than 52 per cent.

The granites are included in the acid group The granites are included in the acid group of plutonic rocks,of plutonic rocks, the syenites and diorites the syenites and diorites are of the intermediate group, and the are of the intermediate group, and the gabbro family forms basic group.gabbro family forms basic group.

GRANITEGRANITE Granite is the best known igneous stone.Granite is the best known igneous stone.

It is usually light – coloured (especially light It is usually light – coloured (especially light grey), formed mainly of potash, feldspar, grey), formed mainly of potash, feldspar, quartz and mica, hornblende and augite are quartz and mica, hornblende and augite are sometimes represented in addition to or in sometimes represented in addition to or in place of mica.place of mica.

Fine granite has a Fine granite has a salt – and - pepper salt – and - pepper pattern,pattern, but feldspar may but feldspar may reddenredden it. it.

The colour of a granite and its hardness and The colour of a granite and its hardness and durability is determined by the composition durability is determined by the composition of the feldspar in it.of the feldspar in it.

Granites are extremely hard, durable and Granites are extremely hard, durable and strongstrong..

They take a good polish and are therefore They take a good polish and are therefore easily kept clean when employed in polluted easily kept clean when employed in polluted atmospheres.atmospheres.

Owing to their great hardness, granites are Owing to their great hardness, granites are difficult to work, and so they are expensive.difficult to work, and so they are expensive.

The rich coloured appearance of certain The rich coloured appearance of certain granites make them most suitable for granites make them most suitable for decorative use. decorative use.

Colours include red, pink, yellow, green, blue, Colours include red, pink, yellow, green, blue, white, black and brown.white, black and brown.

Granite has a wide variety of uses in building, Granite has a wide variety of uses in building, including flooring, interior and exterior wall including flooring, interior and exterior wall facing, column, stair treads, etc.facing, column, stair treads, etc.

SYENITESYENITE

Syenite has a mottled appearance, Syenite has a mottled appearance, with dark green markings and light-with dark green markings and light-coloured patches.coloured patches.

It is hard, durable, strong and more It is hard, durable, strong and more easily worked than granite.easily worked than granite.

Quartz is usually absent, feldspar is Quartz is usually absent, feldspar is the prevalent mineral, hornblende is the prevalent mineral, hornblende is present, and the mica content is present, and the mica content is usually less than in granite.usually less than in granite.

DIORITEDIORITE

Diorite is difficult to work, and this in Diorite is difficult to work, and this in addition to its dull green or black addition to its dull green or black colour, renders it unsuitable for colour, renders it unsuitable for building purposes.building purposes.

It is sometimes known as green It is sometimes known as green stone and is used as road metal.stone and is used as road metal.

Feldspar, hornblende, augite and Feldspar, hornblende, augite and dark mica are present and quartz is dark mica are present and quartz is usually absent. usually absent.

GABBROGABBRO

Gabbro is rarely used for building Gabbro is rarely used for building purposes on account of its bad purposes on account of its bad weathering qualities and its dull weathering qualities and its dull appearance.appearance.

Feldspar, hornblende, augite are the Feldspar, hornblende, augite are the chief minerals of gabbro. chief minerals of gabbro.

B- B- Hypabyssal rocks:Hypabyssal rocks: These were masses of molten These were masses of molten

material which penetrated the material which penetrated the overlying strata, and erosion of the overlying strata, and erosion of the latter has exposed these rocks at latter has exposed these rocks at the surface.the surface.

Cooling of the masses was more Cooling of the masses was more rapid than with the plutonic rocks, rapid than with the plutonic rocks, and their texture is therefore finer.and their texture is therefore finer. (For example: Quartz Porphyries) (For example: Quartz Porphyries)

C- C- Volcanic rocksVolcanic rocks Volcanic rocksVolcanic rocks have been have been formed from formed from

lavalava poured out at the surface of the poured out at the surface of the volcanoes.volcanoes.

Rapid cooling and hardening caused the Rapid cooling and hardening caused the material to be fine grained and of glassy material to be fine grained and of glassy character.character.

Their group classification are rhyolites Their group classification are rhyolites (acid), trachytes and andesites (acid), trachytes and andesites (intermediate) and basalt (basic). (intermediate) and basalt (basic).

SEDIMENTARY STONESSEDIMENTARY STONES Most of these rocks are formed of Most of these rocks are formed of

fragments of igneous rocks which have fragments of igneous rocks which have been deposited by water in layers. been deposited by water in layers.

As successive layers were formed, these As successive layers were formed, these sediments became hardened and sediments became hardened and consolidated by great pressure and were consolidated by great pressure and were cemented together by sandy or clayey cemented together by sandy or clayey paste or by a chemical substance (such paste or by a chemical substance (such as carbonate of lime) conveyed by the as carbonate of lime) conveyed by the percolating water.percolating water.

Other rocks of this division are formed Other rocks of this division are formed from the remains of marine organisms from the remains of marine organisms (shellfish, etc.) and chemically by (shellfish, etc.) and chemically by precipitation. precipitation.

Sedimentary stonesSedimentary stones are chiefly are chiefly employed for building purposes.employed for building purposes.

The principal sedimentary rocks are The principal sedimentary rocks are sandstones and limestones.sandstones and limestones.

SANDSTONESANDSTONE Sandstones consist of grains of quartz held Sandstones consist of grains of quartz held

together by a cement.together by a cement. In addition to quartz, sandstones may contain In addition to quartz, sandstones may contain

such minerals as mica, feldspar, hornblende such minerals as mica, feldspar, hornblende and oxides of iron, resulting in considerable and oxides of iron, resulting in considerable variation in colour and texture.variation in colour and texture.

The hardness and durability of the particular The hardness and durability of the particular sandstone depends on the type of cement.sandstone depends on the type of cement.

The principle cements are The principle cements are siliceous and siliceous and calcareouscalcareous..

Sandstones are classified according to the Sandstones are classified according to the nature of the binding material, thus, siliceous nature of the binding material, thus, siliceous sandstones and calcareous sandstones.sandstones and calcareous sandstones.

Siliceous Siliceous SSandstonesandstones

The grains of these stones are held The grains of these stones are held together together by siliceous cement. by siliceous cement.

Such sandstones are exceedingly Such sandstones are exceedingly durabledurable, , as the silica has good cementing as the silica has good cementing properties and properties and is not attacked by acidsis not attacked by acids in in the atmosphere.the atmosphere.

They are They are very hardvery hard and are usually and are usually difficult difficult to work.to work.

Calcareous sandstonesCalcareous sandstones The grains are bound together The grains are bound together by calcareous by calcareous

cementcement, which is composed of calcite , which is composed of calcite (crystals of carbonate of lime).(crystals of carbonate of lime).

Calcite has good binding qualities but it Calcite has good binding qualities but it is not is not durabledurable if exposed to polluted atmospheres if exposed to polluted atmospheres owing to the acids attackingowing to the acids attacking the matrix and the matrix and loosening the grains of sand which gradually loosening the grains of sand which gradually become removed by the weather.become removed by the weather.

These stones are These stones are easily worked.easily worked. Colours are available in such varieties as Colours are available in such varieties as

blue, brown, yellow, and many mixed blue, brown, yellow, and many mixed varieties.varieties.

LIMESTONELIMESTONE Limestones are composed mainly of two Limestones are composed mainly of two

basic ingredients:basic ingredients:- - calcium carbonate and calcium carbonate and - - magnesium carbonatemagnesium carbonate

with silica, aluminium oxide and iron oxide, with silica, aluminium oxide and iron oxide, together with other elements in lesser together with other elements in lesser amounts, present in most limestones.amounts, present in most limestones.

Limestone is one of the most commonly Limestone is one of the most commonly used building stones.used building stones.

Limestone varies widely in colour and Limestone varies widely in colour and texture.texture.

There are mainly three types of limestone:There are mainly three types of limestone:

There are mainly three types of There are mainly three types of limestone:limestone:

Oolitic limestoneOolitic limestone is a calcite cemented is a calcite cemented calcareous stone formed of shells and shell calcareous stone formed of shells and shell fragments, particularly non - crystalline in fragments, particularly non - crystalline in nature. nature.

Dolomitic limestoneDolomitic limestone is rich in magnesium is rich in magnesium carbonate and frequently somewhat carbonate and frequently somewhat crystalline in character. It usually has greater crystalline in character. It usually has greater compressive and tensile strength than oolitic compressive and tensile strength than oolitic limestones, with greater variety of texture. limestones, with greater variety of texture.

Crystalline limestoneCrystalline limestone is predominantly is predominantly composed of calcium carbonate crystals. It composed of calcium carbonate crystals. It has high compressive and tensile strength, is has high compressive and tensile strength, is very low in absorption and has a smooth very low in absorption and has a smooth texture. The colour is fairly uniform light grey.texture. The colour is fairly uniform light grey.

TRAVERTINETRAVERTINE Travertine is composed mainly of calcium Travertine is composed mainly of calcium

carbonate.carbonate. It has been formed at the earth’s surface It has been formed at the earth’s surface

through the evaporation of water from hot through the evaporation of water from hot springs.springs.

It is used as an interior decorative stone It is used as an interior decorative stone because of its pleasing texture.because of its pleasing texture.

Colours include white, grey, to creamy buff Colours include white, grey, to creamy buff (devetüyü, sarımsı kahverengi).(devetüyü, sarımsı kahverengi).

Travertine is produced primarily as ashlar Travertine is produced primarily as ashlar veneer, rubble and rustic cut stoneveneer, rubble and rustic cut stone..

METAMORPHIC STONESMETAMORPHIC STONES These are either igneous or sedimentary These are either igneous or sedimentary

rocks which have been altered or rocks which have been altered or metamorphosed by heat (from the metamorphosed by heat (from the earth’s interior) or pressure (caused by earth’s interior) or pressure (caused by the weight of superimposed layers of the weight of superimposed layers of material or to the movement of the material or to the movement of the earth’s crust) or a combination of both.earth’s crust) or a combination of both.

As a result of this metamorphism, the As a result of this metamorphism, the original structure of the rocks has been original structure of the rocks has been destroyed, the destroyed, the arrangement of the arrangement of the particles being changed.particles being changed.

The chief metamorphic rocks used for The chief metamorphic rocks used for building purposes building purposes are marbles, slates, are marbles, slates, schist, gneiss and quartzite.schist, gneiss and quartzite.

MARBLEMARBLE Marble is re-crystallised limestone.Marble is re-crystallised limestone. It may be white, yellow, brown, green, It may be white, yellow, brown, green,

grey, red, pink, or black. The great range grey, red, pink, or black. The great range of colours is due to the presence of various of colours is due to the presence of various oxides of iron, silica, and mica. oxides of iron, silica, and mica.

Certain varieties of marble deteriorate Certain varieties of marble deteriorate quite readily when exposed to the weather quite readily when exposed to the weather and are suitable only for interior work.and are suitable only for interior work.

Marble is used mainly for wall or column Marble is used mainly for wall or column facing and for flooring. facing and for flooring.

It is softer and less resistant to weathering It is softer and less resistant to weathering than granite. than granite.

SLATESLATE Slate is formed by the metamorphosis of Slate is formed by the metamorphosis of

clays and shales which have been deposited clays and shales which have been deposited in layers.in layers.

A unique characteristic of the material is that A unique characteristic of the material is that it may be separated into thin, tough sheets it may be separated into thin, tough sheets called slates.called slates.

The basic ingredients include silicon dioxide The basic ingredients include silicon dioxide (45 to 56 percent), aluminium oxide (16 to 25 (45 to 56 percent), aluminium oxide (16 to 25 percent), iron oxide (5 to 8 percent), percent), iron oxide (5 to 8 percent), potassium oxide (3 to 6,5 percent), potassium oxide (3 to 6,5 percent), magnesium oxide (2 to 4 percent), with magnesium oxide (2 to 4 percent), with smaller amounts of titanium, calcium, and smaller amounts of titanium, calcium, and sulfur. sulfur.

Slate is frequently a blue-grey colour but may Slate is frequently a blue-grey colour but may be green, red or brown. It may be used into be green, red or brown. It may be used into sheets used for roofing or flagstones. sheets used for roofing or flagstones.

QUARTZITEQUARTZITE Quartzite is a type of stone which is Quartzite is a type of stone which is

sometimes confused with granite but is quite sometimes confused with granite but is quite different in composition; it is a stone which is different in composition; it is a stone which is harder than some granites.harder than some granites.

It is made of grains of quartz sand cemented It is made of grains of quartz sand cemented together with silica and is usually together with silica and is usually distinguishable by its coarse, crystalline distinguishable by its coarse, crystalline appearance.appearance.

Because of its coarse appearance, quartzite Because of its coarse appearance, quartzite is often used where a rustic effect is required.is often used where a rustic effect is required.

Colours include ivory, tan, red, grey, brown Colours include ivory, tan, red, grey, brown and buff. Characteristically, each stone and buff. Characteristically, each stone contains several colours. contains several colours.

PROPERTIES OF STONESPROPERTIES OF STONESTYPES OF TYPES OF STONESTONE

WEIGHT WEIGHT (kg/m3)(kg/m3)

COMPRESSIVCOMPRESSIVE STRENGTH E STRENGTH

(MPa)(MPa)

WATER WATER ABSORPTIOABSORPTION N (Percent by (Percent by

weight)weight)

GRANITEGRANITE 2643 - 2643 - 32043204

139 - 309139 - 309 0.002 – 0.20.002 – 0.2

SANDSTONSANDSTONEE

2242 - 2242 - 26432643

31 - 10831 - 108 1.5 – 61.5 – 6

LIMESTONELIMESTONE 2000 - 2000 - 28802880

19 - 19319 - 193 0.25 – 7.50.25 – 7.5

MARBLEMARBLE 2963 - 2963 - 30433043

93 - 16293 - 162 0.001 – 0.060.001 – 0.06

SLATESLATE 2800 - 2800 - 28802880

124 - 185124 - 185 0.15 – 0.250.15 – 0.25

GRADES OF STONEGRADES OF STONE

Stone is generally graded into four Stone is generally graded into four groups for construction purposes. groups for construction purposes. They are:They are:

STATUARY, STATUARY,

SELECT,SELECT,

STANDARD and STANDARD and

RUSTIC RUSTIC

in descending order of quality.in descending order of quality. Fineness of grain or texture is the Fineness of grain or texture is the

basis for this classification. basis for this classification.

TYPES AND FORMS OF SOME STONES THAT ARE TYPES AND FORMS OF SOME STONES THAT ARE FREQUENTLY USED IN ARCHITECTURAL APPLICATIONSFREQUENTLY USED IN ARCHITECTURAL APPLICATIONS

TYPES OF TYPES OF STONESTONE

AREAS OF AREAS OF USEUSE

AVAILABLE SIZESAVAILABLE SIZES

THICKNESSTHICKNESS WIDTHWIDTH LENGTHLENGTH

SLATE (FROM SLATE (FROM QUARRY)QUARRY)

PavingPaving 30 – 100 mm30 – 100 mm FreeFree FreeFree

Floor coveringFloor covering 30 – 50 mm30 – 50 mm FreeFree FreeFree

Wall coveringWall covering 30 – 50 mm30 – 50 mm FreeFree FreeFree

Roof coveringRoof covering 4 – 10 mm4 – 10 mm Ranges between Ranges between 150 – 350 150 – 350

mmmm

Ranges between Ranges between 250 – 600 250 – 600

mmmm

TRAVERTINE TRAVERTINE AND AND

MARBLESMARBLES

PavingPaving 20 – 30 mm20 – 30 mm Free & 300 mm Free & 300 mm fixedfixed

FreeFree

Floor coveringFloor covering 20 – 30 mm20 – 30 mm Free & 300 mm Free & 300 mm fixedfixed

Free & 300 mm Free & 300 mm fixedfixed

Wall coveringWall covering 20 mm20 mm Free & 300 mm Free & 300 mm fixedfixed

Free & 300 mm Free & 300 mm fixedfixed

StairsStairs Risers: Risers: 2020 mm mmSteps: Steps: 3030 mm mm

Free & 300 mm Free & 300 mm fixedfixed

Free & 300 mm Free & 300 mm fixedfixed

Roof coveringRoof covering Not applicableNot applicable Not applicableNot applicable Not applicableNot applicable

Stones that are to be used to build rubble Stones that are to be used to build rubble walls come from quarry.walls come from quarry.

But those stones to be used to built ashlar But those stones to be used to built ashlar wall must be cut into exact sizes at the wall must be cut into exact sizes at the specialised workshops.specialised workshops.

Those sedimentary stones that are used Those sedimentary stones that are used mostly as veneers of different types of mostly as veneers of different types of walls and those that are frequently used to walls and those that are frequently used to build fine places are available in fixed build fine places are available in fixed thickness and widths.thickness and widths.

Their length is usually free (i.e. in different Their length is usually free (i.e. in different lengths ranging from 1.00 m to 1.50 m lengths ranging from 1.00 m to 1.50 m

PROCESSING OF MARBLEPROCESSING OF MARBLE Quarried marble are first transported in bulky Quarried marble are first transported in bulky

sizes to marble plants.sizes to marble plants. Here there by the help of big cranes cut into Here there by the help of big cranes cut into

thin layers and exact sizes depending on the thin layers and exact sizes depending on the way that the company markets its product.way that the company markets its product.

There are many ways in which the marble There are many ways in which the marble products may be marketed:products may be marketed:

1- 1- thickness and width of pieces are thickness and width of pieces are fixed, fixed, thethe length is freelength is free

2- 2- limited thickness of 1 cm, width and limited thickness of 1 cm, width and length length fixed by 30 x 30 cm and marketed fixed by 30 x 30 cm and marketed in boxes, in boxes, each for 1 sqm.each for 1 sqm.

3- 3- Marble, reinforced with fiberglass Marble, reinforced with fiberglass backing, backing, with sizes of 6 mm in thickness, with sizes of 6 mm in thickness, 30.5 x 61 or 30.5 x 61 or 60.5 x 60.5 etc.60.5 x 60.5 etc.

BUILDING STONE BUILDING STONE REQUIREMENTSREQUIREMENTS

Despite the abundance of rock, relatively few Despite the abundance of rock, relatively few stones satisfy the requirements as building stones satisfy the requirements as building stones.stones.

The important requirements are:The important requirements are:1) 1) strength,strength,2) hardness, 2) hardness, 3) workability,3) workability,4) durability, 4) durability, 5)5) colour and graincolour and grain,,6) porosity and texture,6) porosity and texture,7) ease of quarrying, and7) ease of quarrying, and8) accessibility.8) accessibility.