Tephrite

Shale

Tephrite and Shale

Tephrite

Shale

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Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles

History

Origin

Germany

Discoverer

Van Tooren

Johann Gottlob Lehmann

Etymology

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

From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,

Class

Igneous Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Clastic, Splintery

Color

Black, Brown, Green, Grey, White

Black, Brown, Buff, Green, Grey, Red, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Muddy

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

Landscaping

Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Other Uses

Commercial Uses

Production of Lime, Soil Conditioner

Creating Artwork, Pottery

Types

Igneous rock

Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale

Features

Host Rock for Lead

Easily splits into thin plates, Generally rough to touch, Very fine grained rock

Archaeological Significance

Monuments

Famous Monuments

Jantar Mantar in India

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

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.

Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.

Composition

Mineral Content

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides

Compound Content

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Ca, Fe, Mg, Silicon Dioxide, Sodium

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

6.53

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Uneven

Streak

Bluish Black

White

Porosity

Very Less Porous

Highly Porous

Luster

Subvitreous to Dull

Dull

Compressive Strength

90.00 N/mm²95.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Slaty

Toughness

2.4

2.6

Specific Gravity

2.862.2-2.8

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³2.4-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.39 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, China, India, Russia

Africa

Namibia, Uganda

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

Germany, Hungary, Italy, Portugal, Spain

Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland

Others

Deposits in Western Continents

North America

USA

South America

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, New Zealand, Queensland, Victoria, Western Australia

All about Tephrite and Shale Properties

Know all about Tephrite and Shale properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite belongs to Igneous Rocks while Shale belongs to Sedimentary Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Shale is Clastic, Splintery. Tephrite appears Vesicular and Shale appears Muddy. The luster of Tephrite is subvitreous to dull while that of Shale is dull. Tephrite is available in black, brown, green, grey, white colors whereas Shale is available in black, brown, buff, green, grey, red, yellow colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Shale are creating artwork, pottery.