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PREPAID BY:- GROUP :C•RAJ KRUNAL•SHAH APURVA•PATHARIYA SARASWATI

CIVIL ENGINEERINGSIGMA INSTITUTE OF ENGINEERING

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TOPICS TO BE COVERD

INTRODUCTION

PHYSICAL PROPERTIES OF MINERALS

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INTRODUCTION

MINERAL-: A naturally occurring homogeneous substance which has a more or less definite atomic structure .

MINERAL

ROCK FORMING MINERALS

ORE FORMING MINERALS

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PHYSICAL PROPERTIES OF MINERALS

Determine by simple test.

Useful on field for recognizing.

Identification by polarizing microscope by cutting minerals into thin slices and passing polarized light to pass through them.

PHYSICAL PROPERTIES OF MINERAL ARE:-

1) COLOURS 9)TENACITY

2) STREAK 10)MAGNETISM

3) LUSTRE 11)FLUORESCENCE

4) HARDNESS 12)SPECIFIC GRAVITY

5) HABIT 13)FORM

6) CLEAVAGE

7) FRACTURE

8) FEEL

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COLOURS Absorption of the certain

wave lengths of light by atoms making up the crystal.

Colour and appearance in light depends upon the composition and structure of the substance.

Phenomenon shown by minerals:-

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a) PLAY OF COLOURS:- It is the development of series of prismatic colour shown by some on turning them in light. E.g.: Diamond

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b) CHANGE OF COLOURS:-It is similar to play of colour except that the rate of change of colour on rotation is rather low. E.g.: Plagioclase Feldspar.

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c)IRIDESCENCE: Some minerals shows rainbow colours either in their exterior or in the interior surface.E.g.:-Limonite.

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STREAK The colour

of mineral powder is called the streak.

Obtained by rubbing the mineral against an unglazed porcelain plate , called the “streak plate”, .

Important in case of coloured minerals which often give a much lighter streak the their original body colour .

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LUSTURE The way of mineral, which

reflect the light from its surface and may define as shine of mineral.

There are two types of lusture:-

1)Metallic lusture

2)Non-metallic lusture

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METALLIC LUSTURE

NON-METALLIC LUSTURE

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HARDNESS Define as the resistance of a

mineral to scratching or abrasion.

Hardness is determined by rubbing a mineral of unknown hardness against one of known hardness.

Obtained by using “mohs scale of hardness". It can also be obtained by 1)scratch with finger nails , 2)a penknife, 3)penny

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FINGER NAILS PENNY

BY KNIFE

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HABIT “Habit” of a mineral may be

define as the size and shape of the crystals, and the structure or form shown by the crystal.

1)Accicular :- Minerals showing needle like crystals.

E.g.:-Natrolite.

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2)Fibrous:-Minerals showing an aggregate of long thin fibers. E.g.:-Asbestos.

3)Tabular:-Minerals showing bladed habit occur as small knife blades.E.g.:-Kyanite.

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4)Granular:-Minerals which occur as aggregate of equidimensional grains.E.g.:-Chromites.

5)Pisolitic:-Minerals which occur as aggregates of rounded grains of a pea size. E.g.:-Bauxite.

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6)Botryoidal:-Minerals showing aggregate of rounded masses resembling bunch of grapes. E.g.:-Chalcedony.

7)Columnar:-Minerals showing columnar crystals.

E.g.:- Tourmaline.

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CLEAVAGE The tendency of a mineral to break

more easily with smooth surfaces along planes of weak bonding.

It is the property which is related to the atomic arrangement within the mineral. For E.G.:-Mica,Galena,Calcite.

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Mica has basal cleavage.

Calcite has rhombohedral cleavage.

Galena has cubic cleavage.

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FRACTURE

The way a mineral breaks when it does not yield along cleavage or parting surface , it is called Fracture.

Fracture are neither linear nor parallel.

CONCHOIDAL FRACTURE

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EVEN FRACTURE:- Fracture surface which is almost flat.

UNEVEN FRACTURE:- Fracture surface which is irregular or rough.

E.g.:DUMORTIERITE

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Minerals can be identified by how they break.  Obsidian (left), although not a mineral because of its lack of crystal structure, shows excellent conchoidal fracture.  Asbestos (right), which is the common name for several minerals that form thin, threadlike structures, is an example of a mineral with fibrous fracture.

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FEEL Feel is the sensation upon touching or

handling minerals .the different types of feel are “greasy” , “soapy”, “rough” , and “harsh” .

Talc has “greasy” feel.

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Kaolin has “Soapy” feel.

Bauxite has “Rough” feel.

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TENACITY

Tenacity of mineral denotes the degree or character of cohesion.

Tenacity is classified as follows:-

1)Sectile:-Mineral which may be cut with knife but slices are not malleable.

ORPIMENT

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2)Malleable:-Minerals which flatten under the hammer.

GOLD

3)Flexible:-Minerals which may be bent.

GYPSUM

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MAGNETISM

A few minerals are attracted by magnet . Of these minerals magnetite and pyrrhotite are the most common examples. The magnetite that possesses attracting power and polarity is called “Lodestone”.

MAGNETITE

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FLUORESCENCE

Some minerals when exposed in sunlight or ultraviolet light, produce a colour quit different from their own. Thus green or colourless fluorite shows a blue or purple colour in ultraviolet light. This property of minerals is called “Fluorescence”.

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GREEN FLUORITE

SHOWS BLUE OR PRPULE COLOUR

IN SUNLIGHT

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SPECIFIC GRAVITY

“Specific gravity” is a number which represents the ratio of the weight of a mineral to the weight of an equal volume of water. Thus a mineral with specific gravity 4.0 is four times as heavy as water.

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FORM

The internal atomic arrangement of a mineral is manifested outwardly by development of geometrical shapes of crystal structure.

CALCIT INTERNAL CRYSTAL STRUCTURE

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COMPARISION OF MINERALSMINERALS PYRITE HEMATITE

FORMULA FeS2 Fe3O3

IMAGE

COLOUR BRASS YELLOW REDDISH BROWN OR BLACK

LUSTURE METALLIC METALLIC TO DULL

STREAK GREENISH OR BROWNISH BLACK

DARK RED

HARDNESS 6-6.5 5-6

HABIT COMMON FORMS ARE THE CUBE

CRYSTALS THIN TABULAR

USE MANUFACTURE OF SULFURIC ACID

AS IRON ORE,AS PIGMENT

CLEVAGE - ABSENT

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MINERAL MAGNETITE BAUXITE

FORMULA Fe3O4 Al2O3

IMAGE

COLOUR IRON BLACK WHITE,GRAY,YELLOW,BROWN

LUSTURE METALLIC TO DULL DULL EARTHY

STREAK BLACK YELLOW TO BROWN

HARDNESS 6 2-2.5

HABIT OCTAHEDRAL CRYSTAL,MASSIVE OR GRANULAR

PISOLITIC

USE IMPORTANT ORE OF IRONAS ABRASIVE MATERIAL,IMPORTANT ORE OF ALUMINIUM

CLEVAGE ABSENT ABSENT

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MINERAL GYPSUM DOLOMITE

FORMULA CaSO4.2H2O CaMg(CO3)2

IMAGE

COLOUR COLOURLESS,WHITE,GREY,RED OR BROWN

WHITE,GRAY TO PINK

LUSTURE USUALLY VITREOUS VITREOUS TO PEARLY

STREAK WHITE WHITE

HARDNESS 2 3.5-4

HABIT TABULAR,FIBROUS,GRAN-NULAR.

CRYSTAL SHOW CURVED FACES

USE POP , AS FERTILIZER AS BUILDING & ORNAMENTAL STONE

CLEAVAGE PERFECT PERFECT ON RHOMBOHEDRAL CLEAVAGE

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MINERAL CALCITE GRAPHITE

FORMULA CaCO3 C

IMAGE

COLOUR USUALLY WHITE TO COLOURLESS

IRON BLACK TO STEEL GRAY

LUSTURE VITREOUS METALLIC ,EARTHY

STREAK WHITE BLACK

HARDNESS 3 1-2

HABIT CRYSTALLINE,TABULAR,GRANULAR

USE MANUFACTURE OF CEMENT AND LIME.

STEEL MAKING,LUBRICANTS

CLEVAGE PERFECT WITH 74 55’ PERFECT

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MINERAL CHALCOCITE GALENA

FORMULA Cu2S PbS

IMAGE

COLOUR DARK GRAY TO BLACK LEAD GRAY AND SILVER

LUSTURE METALLIC BRIGHT METALLIC

STREAK SHINY BLACK TO LEAD GRAY

LEAD GRAY

HARDNESS 2.5-3 2.5

HABIT SHORT PRISMATIC CRSTAL,MASSIVE

OFTEN CUBIC CRYSTAL,MASSIVE

USE IMPROTANT ORE OF COPPER

IMPORTANT ORE OF LEAD AND SILVER

CLEAVAGE POOR PERFECT CUBIC

REFERENCE:- BOOK:”PRINCIPLES OF ENGINEERING

GEOLOGY”

by,” B.M BANGAR”

GOOGLE IMAGES.

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