Banded iron formation

Pegmatite

Banded iron formation and Pegmatite

Banded iron formation

Pegmatite

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Definition

Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

History

Origin

Western Australia, Minnesota

Discoverer

Johann Gottlob Lehmann

R. J. Hauy

Etymology

From its formation process

From Greek pegma, pegmat which means- thing joined together + -ite

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Texture

Banded, Trellis

Pegmatitic

Color

Red, Reddish Brown

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

Paving Stone, Office Buildings

As Building Stone, As Facing Stone, Paving Stone

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

As Dimension Stone, Used for flooring, stair treads, borders and window sills.

As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

As a touchstone, Cemetery Markers, Creating Artwork

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Types

Algoma-type , Lake Superior-type, Superior-type and Taconite

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Features

Is one of the oldest rock

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

The banded iron layers are formed in sea water when oxygen is released by photosynthetic cyano-bacteria. The oxygen then combines with dissolved iron in ocean to form insoluble iron oxides, which precipitated out, forming a thin layer of banded iron formation on ocean floor.

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

Composition

Mineral Content

Hematite, Magnetite, Quartz

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Compound Content

Fe, Iron(III) Oxide, Silicon Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

5.5-67

1 7

👆🏻

Grain Size

Large and Coarse Grained

Medium to Coarse Grained

Fracture

Uneven, Splintery or Conchoidal

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Earthy

Grainy, Pearly and Vitreous

Compressive Strength

220.00 N/mm²178.54 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.5

2.1

Specific Gravity

5.0-5.32.6-2.63

0 8.4

👆🏻

Transparency

Translucent to Opaque

Density

-9999 g/cm³2.6-2.65 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

3.20 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Africa

Kenya, Morocco, South Africa, Tanzania

South Africa

Europe

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada

South America

Bolivia, Brazil

Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

All about Banded iron formation and Pegmatite Properties

Know all about Banded iron formation and Pegmatite properties here. All properties of rocks are important as they define the type of rock and its application. Banded iron formation belongs to Sedimentary Rocks while Pegmatite belongs to Igneous Rocks.Texture of Banded iron formation is Banded, Trellis whereas that of Pegmatite is Pegmatitic. Banded iron formation appears Layered, Banded, Veined and Shiny and Pegmatite appears Layered, Banded, Veined and Shiny. The luster of Banded iron formation is earthy while that of Pegmatite is grainy, pearly and vitreous. Banded iron formation is available in red, reddish brown colors whereas Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Banded iron formation are as a touchstone, cemetery markers, creating artwork and that of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz.