Banded iron formation

Variolite

Banded iron formation and Variolite

Banded iron formation

Variolite

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1 Definition

1.1 Definition

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

Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance

1.2 History

1.2.1 Origin

Western Australia, Minnesota

France

1.2.2 Discoverer

Unknown

1.3 Etymology

From its formation process

From Latin varius, speckled, variegated

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Banded, Trellis

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

2.2 Color

Red, Reddish Brown

Black, Brown, Light to Dark Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Layered, Banded, Veined and Shiny

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes

Floor Tiles, Flooring, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

Paving Stone, Office Buildings

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Curbing, Whetstones

Curbing

3.2 Industry

3.2.1 Construction Industry

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

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

As a touchstone, Cemetery Markers, Creating Artwork

Cemetery Markers, Creating Artwork

4 Types

4.1 Types

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

Not Available

4.2 Features

Is one of the oldest rock

Has High structural resistance against erosion and climate, Very fine grained rock

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Present

Absent

5 Formation

5.1 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.

Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.

5.2 Composition

5.2.1 Mineral Content

Hematite, Magnetite, Quartz

Olivine, Plagioclase, Pyroxene

5.2.2 Compound Content

Fe, Iron(III) Oxide, Silicon Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

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

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Coastal Erosion, Wind Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5.5-66

1 7

6.1.2 Grain Size

Large and Coarse Grained

Not Applicable

6.1.3 Fracture

Uneven, Splintery or Conchoidal

Conchoidal

6.1.4 Streak

White

White to Grey

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Earthy

Not Available

6.1.7 Compressive Strength

NA37.50 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

Not Available

6.1.9 Toughness

1.5

2.3

6.1.10 Specific Gravity

5.0-5.32.8-3

0 8.4

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

Not Available2.9-3.1 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

3.20 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

India, Russia

7.1.2 Africa

Kenya, Morocco, South Africa, Tanzania

South Africa

7.1.3 Europe

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

Iceland

7.1.4 Others

Greenland, Mid-Atlantic Ridge

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Bolivia, Brazil

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, Queensland, South Australia, Western Australia

Not Yet Found

All about Banded iron formation and Variolite Properties

Know all about Banded iron formation and Variolite 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 Variolite belongs to Igneous Rocks.Texture of Banded iron formation is Banded, Trellis whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Banded iron formation appears Layered, Banded, Veined and Shiny and Variolite appears Dull and Soft. The luster of Banded iron formation is earthy while that of Variolite is not available. Banded iron formation is available in red, reddish brown colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Banded iron formation and Variolite are as a touchstone, cemetery markers, creating artwork.