Tephrite

Variolite

Tephrite and Variolite

Tephrite

Variolite

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1 Definition

1.1 Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

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

Germany

France

1.2.2 Discoverer

Van Tooren

Unknown

1.3 Etymology

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

From Latin varius, speckled, variegated

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

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

Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

2.2 Color

Black, Brown, Colourless, Green, Grey, White

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

Vesicular

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

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

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Landscaping

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Production of Lime, Soil Conditioner

Cemetery Markers, Creating Artwork

4 Types

4.1 Types

Not Available

4.2 Features

Host Rock for Lead

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

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

5 Formation

5.1 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.

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

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Olivine, Plagioclase, Pyroxene

5.2.2 Compound Content

CaO, Carbon Dioxide, MgO, 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

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

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

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.56

1 7

6.1.2 Grain Size

Medium to Fine Coarse Grained

Not Applicable

6.1.3 Fracture

Uneven

Conchoidal

6.1.4 Streak

Bluish Black

White to Grey

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Subvitreous to Dull

Not Available

6.1.7 Compressive Strength

90.00 N/mm²37.50 N/mm²

0.15 450

6.1.8 Cleavage

Crenulation and Pervasive

Not Available

6.1.9 Toughness

2.4

2.3

6.1.10 Specific Gravity

2.862.8-3

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.8-2.9 g/cm³2.9-3.1 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Not Yet Found

India, Russia

7.1.2 Africa

Namibia, Uganda

South Africa

7.1.3 Europe

Germany, Hungary, Italy, Portugal, Spain

Iceland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

USA

Canada, USA

7.2.2 South America

Not Yet Found

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, Western Australia

Not Yet Found

All about Tephrite and Variolite Properties

Know all about Tephrite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Variolite belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Tephrite appears Vesicular and Variolite appears Dull and Soft. The luster of Tephrite is subvitreous to dull while that of Variolite is not available. Tephrite is available in black, brown, colourless, green, grey, white colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Variolite are cemetery markers, creating artwork.