Home > Materials Specifications

Rock Forming Minerals

Er. Parbhakar Dwivedi
0
 

       

The igneous rocks contain many minerals. The various natural minerals having range of different distinctive characteristics are available. But only few of them form the bulk of rocks. These minerals are called the rock-forming minerals.

(1) Minerals in the igneous rocks: Following are the commonly found mineral in the igneous rocks:

(i) Augite: This mineral resembles hornblende except that it is heavier than hornblende. It forms octagonal crystals. It changes to chlorite by hydration. Its density is 23 to 36 kN/m3 and hardness is 5 to 6. It is also called Pyroxene

(ii) Chlorite: It has green colour. It is mainly derived from the decomposition of augite, biotite and hornblende.

(iii) Felspar: It has many varieties, the common being that of orthoclase microcline and one or other Member of the plagioclase series. The orthoclase is whitish, greyish or pinkish in colour. It is a straight-splitting mineral it shows development of tabular crystals. It has usually well-defined faces the presence of decomposed rocks sometimes impart cloudy appearance to this mineral. The rocks disintegrate easily, if orthoclase is in abundance in their structure. The micro line has deep green or flesh-red colour. Is found along with orthoclase.

(iv) Hornblende: This mineral is heavy, strong and durable, but brittle. Its colour is dark-green or black.

It has glassy luster. It frequently occurs as six-sided crystals having the appearance of elongated hexagons. It Chan to chlorite when exposed to weather. Its density is 29 to 30 kN/m3 and hardness is 5 to 6. It is an essential component of many igneous rocks

(v) Mica: It is silicate of aluminium with potassium and occurs in thin transparent lamina or plates. The layers of mica shine with metallic luster. The hardness varies from 2 to 3. The two forms of mica commonly occurring in igneous rocks are muscovite and biotitic. They occur separately or simultaneously the muscovite is also known as the white mica or potash mica. It has light colour and it may be colorless when available in thin layers. Its density varies from 27.60 to 31 kN/m3.

The biotite is also known as the black mica. It has dark colour and metallic lustre. It iron content and hence, when exposed to weather, it changes to chlorite and loses its elasticity. Its density varies from 28 to 32 kN/m3.

(vi) Olivine: It has black, olive-green or yellow colour. It is colorless when found in thin sections. It frequently changes to the serpentine.

(vii) Plagioclase: This is a general name given to a series of feldspars which ranges from sodium aluminium silicate known as the albite to calcium aluminium silicate known as the as the annotate. The Characteristic of Plagioclase is multiple twinning. It is an oblique-splitting mineral.

(viii) Quartz: It is the crystalline form of silica. It is usually colorless. But it may be sometimes brownish, Pink or yellow in colour due to presence of metallic oxides in small quantities. It is weather proof andresists the attack of acids with the exception of hydrofluoric acid. Its density is 26.50 kN/m3 and its hardness is 7. It may be noted that common sand is a variety of quartz. The transparent crystal of quartz is known as the rock crystal. The compact translucent mass of quartz is called the hornstone.

(ix) Serpentine: This mineral resembles chlorite. It has pale-green or yellow colour. It presents a massive appearance.

(2) Minerals in the sedimentary rocks: The sedimentary rocks also contain many minerals. Following are the commonly found minerals in the sedimentary rocks:

(i) Calcite: This mineral rarely occurs in igneous rocks. But it is the chief constituent of many sedimentary rocks. The calcite is calcium carbonate CaCOs and it gives out carbon dioxide when attacked by mineral acids it is generally colorless. But the presence of impurities may give it yellow, brown or red colour. It is available in various shades. It is poorly soluble in water and it reacts vigorously with acids. Its density is 27 kN/m3 and its hardness is 3. It deteriorates in water containing carbon dioxide CO2 since calcium bicarbonate CA (HCO3)2 is formed and it is about 100 times more soluble in water than calcite.

(ii) Magnesite: This mineral occurs rarely in nature and its chemical composition is MgCOs. It is harder and less soluble than calcite.

(iii) Dolomite: It is available in various shades. Its crystals are brittle. It is however stronger and heavier than calcite. It is insoluble in ordinary water. In chemical composition, it is a bicarbonate of magnesium and calcium, MgCO3•CaCOs. It consists of 46% of MgC03 and 54% of CaCO3.

iv) Glauconite: This mineral has no definite crystal form. Its colour varies from yellow to green. It is practically insoluble in acids as well as ordinary water.

(v) Limonite: It has an earthy appearance. Its colour varies from yellow to reddish brown. It is insoluble in ordinary water, but it dissolves in acids.

(vi) Gypsum: It is the hydrated sulphate of calcium with chemical composition as CaSO4 2H2O. It is white when in pure state. Due to presence of impurities, it is tinted into grey, reddish, yellowish or black colours. Its density is 23 kN/m3 and its hardness is 2. It is a crystalline substance. Its solubility in water is very poor.

(vii) Anhydrate: This is an anhydrous variety of gypsum and its chemical composition is CaSO4. Its colour varies from reddish-white grey. Its density varies from 28 to 30 kN/m3 and its hardness varies from 3.00 to 3.50. If it remains in contact with water for a long time, it is converted into gypsum with a slight increase in volume.

Sponsored

PD Consulting Engineers Pvt. Ltd. Transforming construction for a new generation "Cost, Quality & Project management"

QS & Cost management, Bill Checking / Audit, Technical Auditors, Valuation, Contract and Tendering, Project Management, Project Planning, Quality Control, Consulting Engineers, Structural Consultancy

Close


Comment:

Name:

Email:

Civil N Construction Blog



Relevant Topics

Binding Wire Consumption Finish Sizes Tolerances Tensile Wrapping Bend Test Permissible Defective

Tar Classification Of Tar

Reclaimed Rubber Advantages Disadvantages Uses Of Reclaimed Rubber

Comparison Between Asphalt Bitumen Tar

Compounding Of Rubber Compounds Used For Natural Synthetic Rubber

Pitched Roof Coverings Sheets Comparison Between Ac Gi Sheets

Uses Of Rubber Consumption Of Rubber For Various Items

Turpentine Properties Of Turpentine Uses

Properties Of Rubber

Rubber Types Of Rubber

Forms Of Rubber

Vulcanization Effects Of Vulcanization

Sound Absorbent Materials Classifications Materials Are Used For Sound Absorbent

Guidelines For Use Plastic Emulsions Paints

Types Of Paints

Painting On Different Surfaces Woodwork Metal Etc

Notes For Guidance In The Process Of Painting

Polyurethane Sealant

Precautions Taken In The Design Installation Of Pvc Pipes

Polysulphide Sealants

Preventive Measures For Corrosion

Structural Adhesives

Moulding Compounds Types

Advantages And Disadvantages Of Pvc Pipes

Bonding Agents Cement Based Slurries

Biodegradable Plastic Its Advantages Disadvantages

Adhesives Difference Between Sealant And Adhesive

Application Of Epoxy Adhesive

Non Structural Adhesives

Wall Paper Whitewashing Colourwashing

Defects In Painting

Ingredients Of A Distemper Process Of Distempering

Applications Of Frp In Building Industry

Classification Methods Of Polymerization

Distempering Properties Of Distempers

Properties Of Plastics

Processes Involved In The Fabrication Of Articles Of Plastics

Selection Of Material For Injection Grouting

Plastics Composition Of Plastic

Pvc Pipes In Buildings

Properties Of Frp Fibre Glass Reinforced Plastic

Materials Commonly Used as Sealants

Silicone Sealant

Classification Of Sealants

Types Of Varnishes Process Of Varnishing

Various Types Of Grouting Materials

Sealant Consistencies

Uses Of Plastics

Failure Of Paint

Desirable Properties Of Sealant

Bonding Agent Between Old And New Concrete

Varnishing Characteristics Of An Ideal Varnish Ingredients

Fibre Glass Reinforced Plastic Frp Principal Methods

Sealants Functions Of Sealants Procedure

Preventive Measures For Corrosion

Classification Of Sealants

Sealant Consistencies

Desirable Properties Of Sealant

Sealants Functions Of Sealants Procedure

Cold Twisted Deformed Bars Ctd Bars Disadvantages

Magnetic Properties Of Steel

Composition Of Cast Iron

Metals Categories Ferrous Metals

Market Forms Of Steel Steel Available In Market

Use Of Wrought Iron

Factors Influencing Corrosion

Corrosion Of ferrous Metals Non Ferrous Metals

Uses Of Cast Iron

Metal Corrosion Types Of Corrosion Effect Of Corrosion

Heat Treatment Processes Of Steel

Mechanical Treatment Of Steel

Precautions In Using Mortar

Defects In Steel

Pig Iron Manufacture Of Pig Iron

Prevention Of Corrosion Of Steel In Concrete

Forms Of Corrosion

Selection Of Mortar As Per Nature Of Work Type Of Mortar

Nature And Properties Of Metals

Ribbed Hysd Bars High Yielding Strength Deformed Bars

Defects In Wrought Iron

Types Of Pig Iron

Thermo Mechanically Treated Tmt Bars Why Prefer Tmt Over Hysd Bars

Causes Of Corrosion

Defects In Metal Casting

Properties Of Engineering Materials

Is Classification Of Lime

Rock Forming Minerals

Comparison Between Lime And Hydraulic Lime

Physical Properties Of Engineering Materials

Common Building Stones Of India

Uses Of Stones

Mechanical Properties Of Materials

Physical Classification Of Rocks

Classification Materials Based Upon Their Uses

Chemical Classification Of Rocks

Qualities Of Good Building Stone

Lime Classification Of Limes

Textures Of Structure Of A Rock

Classification Of Rocks

Factors Of Corrosion Of Reinforcement

Precautions While Using Epoxies

Physical And Mechanical Properties Of Polymer Modified Mortar Concrete

Special Materials For Repair

Essential Eequirements Of Repair Materials

Classification Of Polymeric Modifiers

Deleterious Effects Of Aggressive Chemicals

Causes Of Deterioration Of Concrete Structures

Application Of polymer Modified Mortar concrete Pmm Pmc In Repairs

Corrosion Of Reinforcement Explained

Advantages Of Using Epoxies As A Repair Material

Types Of Materials Available For Repair

Application Of epoxy Based Materials In Repairs

Gauge Type of Mechanical Gauges

Specifications for cement, Specifications for physical properties of Portland cement

Introduction of Cement, Types of cement

Construction Materials- Introduction, Classification of engineering material, Properties of Engineering Materials

Lift Design Important Factors Traffic Constraints

Classification Of Lifts Rope Hydraulic Lift

Water Requirements For Sprinkler Systems By pipe Schedule Hydraulic Method Calculation

Operating System Automatic Operation Full Selective Collective Duplex Collective

Spacing Area Of Coverage Of Sprinklers Maximum Minimum Distance Between Sprinkler

Lifts Types Of Lifts

Hydraulically Most Demanding Area

Water Requirement For Sprinkler System

Types Of Systems Of Sprinklers

Traffic Analysis For Lift Positioning Occupancy Calculation Of Time Factor

Hydraulic Elevators

Essential Components Of Lifts Elevators Brakes Hoisting Rope Motor Counter Weights

Power Control Ac Resistance Control Variable Frequency Drive

Classification Of Occupancies Firefighting

Important Definition For Sprinkler Firefighting

Classification Of Lift According To Interiors

Pump Capacity Water Storage Requirement

Sprinkler Types Upright Pendant Sidewall System

Piping Of Sprinkler System

Important Points Related To Pipe Selection Laying

Selection On Temperature Rating

Automatic Sprinkler System

Dimensional Structural Requirements For Lift Tolerance Allowed In Structure

---NNNNNNNNNNNNNNNNNNNNNN

Basic Principles Of Water Supply Drainage And Sanitation

Water Supply Requirements For Buildings

Protection Of Water Supply

Estimate Of Demand Load Of Water Supply

Design Of Distribution Systems Of Water Supply

Water Supply Materials Fittings And Appliances

Colour Codes For Different Types Of Water Pipes

Important Water Supply Related Definitions

Consideration For Design Of Water Supply

Water Supply Fixture Units (wsfu) For Ifferent Fixtures With Minimum Pipe sizes

Storage Of Water

Water Sources And Quality

Maximum Flow Rate And Flush Volumes

Sponsored

PD Consulting Engineers Pvt. Ltd. Transforming construction for a new generation "Cost, Quality & Project management"

QS & Cost management, Bill Checking / Audit, Technical Auditors, Valuation, Contract and Tendering, Project Management, Project Planning, Quality Control, Consulting Engineers, Structural Consultancy

Close