Banded iron formation

Tephrite

Banded iron formation and Tephrite

Banded iron formation

Tephrite

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Definition

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

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

History

Origin

Western Australia, Minnesota

Germany

Discoverer

Johann Gottlob Lehmann

Van Tooren

Etymology

From its formation process

From Greek tephra, ashes from Indo-European base, to burn

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Coarse Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Banded, Trellis

Aphanitic to Porphyritic

Color

Red, Reddish Brown

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

Paving Stone, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

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

Landscaping

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Sculpture

Other Uses

Commercial Uses

As a touchstone, Cemetery Markers, Creating Artwork

Production of Lime, Soil Conditioner

Types

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

Igneous rock

Features

Is one of the oldest rock

Host Rock for Lead

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.

Tephrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

Composition

Mineral Content

Hematite, Magnetite, Quartz

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Compound Content

Fe, Iron(III) Oxide, Silicon Dioxide

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact 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

Properties

Physical Properties

Hardness

5.5-66.5

1 7

👆🏻

Grain Size

Large and Coarse Grained

Medium to Fine Coarse Grained

Fracture

Uneven, Splintery or Conchoidal

Uneven

Streak

White

Bluish Black

Porosity

Highly Porous

Very Less Porous

Luster

Earthy

Subvitreous to Dull

Compressive Strength

220.00 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

1.5

2.4

Specific Gravity

5.0-5.32.86

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

-9999 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

3.20 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Africa

Kenya, Morocco, South Africa, Tanzania

Namibia, Uganda

Europe

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

Germany, Hungary, Italy, Portugal, Spain

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Bolivia, Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

New Zealand, Western Australia

All about Banded iron formation and Tephrite Properties

Know all about Banded iron formation and Tephrite 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 Tephrite belongs to Igneous Rocks.Texture of Banded iron formation is Banded, Trellis whereas that of Tephrite is Aphanitic to Porphyritic. Banded iron formation appears Layered, Banded, Veined and Shiny and Tephrite appears Vesicular. The luster of Banded iron formation is earthy while that of Tephrite is subvitreous to dull. Banded iron formation is available in red, reddish brown colors whereas Tephrite is available in black, brown, green, grey, white colors. The commercial uses of Banded iron formation are as a touchstone, cemetery markers, creating artwork and that of Tephrite are production of lime, soil conditioner.