Tephrite

Dacite

Tephrite and Dacite

Tephrite

Dacite

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Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

History

Origin

Germany

Romania and Moldova, Europe

Discoverer

Van Tooren

Unknown

Etymology

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

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

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

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Color

Black, Brown, Green, Grey, White

Bluish - Grey, Brown, Grey, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

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

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

Landscaping

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts

Other Uses

Commercial Uses

Production of Lime, Soil Conditioner

Commemorative Tablets, Creating Artwork

Types

Igneous rock

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Host Rock for Lead

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

Composition

Mineral Content

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Compound Content

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic 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

Properties

Physical Properties

Hardness

6.52-2.25

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fracture

Uneven

Conchoidal

Streak

Bluish Black

White

Porosity

Very Less Porous

Less Porous

Luster

Subvitreous to Dull

Compressive Strength

90.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Perfect

Toughness

2.4

Specific Gravity

2.862.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.8-2.9 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Africa

Namibia, Uganda

Europe

Germany, Hungary, Italy, Portugal, Spain

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

USA

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New Zealand, South Australia, Western Australia

All about Tephrite and Dacite Properties

Know all about Tephrite and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Dacite belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Dacite is Aphanitic to Porphyritic. Tephrite appears Vesicular and Dacite appears Vesicular. The luster of Tephrite and Dacite is subvitreous to dull. Tephrite is available in black, brown, green, grey, white colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Dacite are commemorative tablets, creating artwork.