Greywacke

Tephrite

Greywacke and Tephrite

Greywacke

Tephrite

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Definition

Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

History

Origin

Germany

Discoverer

Unknown

Van Tooren

Etymology

From German Grauwacke, from grau grey + wacke

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

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

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

Texture

Clastic

Aphanitic to Porphyritic

Color

Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar

Landscaping

Medical Industry

Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts, Sculpture

Other Uses

Commercial Uses

As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones

Production of Lime, Soil Conditioner

Types

Greywacke

Igneous rock

Features

Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.

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

Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Compound Content

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

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Sea Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

6-76.5

1 7

👆🏻

Grain Size

Angular and Fine

Medium to Fine Coarse Grained

Fracture

Conchoidal

Uneven

Streak

White

Bluish Black

Porosity

Highly Porous

Very Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

120.00 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Crenulation and Pervasive

Toughness

2.6

2.4

Specific Gravity

2.2-2.82.86

0 8.4

👆🏻

Transparency

Opaque

Density

2.6-2.61 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

Africa

Namibia, Nigeria, South Africa

Namibia, Uganda

Europe

Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom

Germany, Hungary, Italy, Portugal, Spain

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

Deposits in Oceania Continent

Australia

New South Wales, New Zealand

New Zealand, Western Australia

All about Greywacke and Tephrite Properties

Know all about Greywacke and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Greywacke belongs to Sedimentary Rocks while Tephrite belongs to Igneous Rocks.Texture of Greywacke is Clastic whereas that of Tephrite is Aphanitic to Porphyritic. Greywacke appears Dull and Tephrite appears Vesicular. The luster of Greywacke is dull while that of Tephrite is subvitreous to dull. Greywacke and Tephrite are available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones and that of Tephrite are production of lime, soil conditioner.