Picrite

Tephrite

Picrite and Tephrite

Picrite

Tephrite

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Definition

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

History

Origin

Hawaii Islands

Germany

Discoverer

Unknown

Van Tooren

Etymology

From Greek pikros bitter + -ite, 19th century

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

Class

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

Earthy, Rough

Aphanitic to Porphyritic

Color

Black, Brown, Green, Grey, Pink, White, Yellow

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Vesicular

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Sculpture

Other Uses

Commercial Uses

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

Production of Lime, Soil Conditioner

Types

Oceanite

Igneous rock

Features

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Picrite 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.

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

Biotite, Olivine, Plagioclase, Pyrrhotite

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

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

Properties

Physical Properties

Hardness

6.86.5

1 7

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Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Uneven

Streak

White, Greenish White or Grey

Bluish Black

Porosity

Less Porous

Very Less Porous

Luster

Subvitreous to Dull

Compressive Strength

189.00 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.1

2.4

Specific Gravity

2.75-2.922.86

0 8.4

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Transparency

Opaque

Density

1.5-2.5 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.88 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Africa

South Africa

Namibia, Uganda

Europe

Iceland

Germany, Hungary, Italy, Portugal, Spain

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Picrite and Tephrite Properties

Know all about Picrite and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Tephrite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Tephrite is Aphanitic to Porphyritic. Picrite appears Rough and Shiny and Tephrite appears Vesicular. The luster of Picrite and Tephrite is subvitreous to dull. Picrite and Tephrite are available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Tephrite are production of lime, soil conditioner.