Andesite

Picrite

Andesite and Picrite

Andesite

Picrite

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Definition

Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava

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

History

Origin

North America

Hawaii Islands

Discoverer

Theodor von Gümbel

Unknown

Etymology

From Andes mountains, where it is found in abundance

From Greek pikros bitter + -ite, 19th century

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Earthy, Rough

Color

Bluish - Grey, Grey, Pink, Yellow

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Rough and Shiny

Uses

Architecture

Interior Uses

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

Countertops, Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Office Buildings, Roof Tiles

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Cobblestones, Construction Aggregate, for Road Aggregate

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.

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

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

Types

Icelandite

Oceanite

Features

Generally rough to touch, High silica content, Is one of the oldest rock

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Middle of the Earth in Ecuador

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.

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.

Composition

Mineral Content

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

Biotite, Olivine, Plagioclase, Pyrrhotite

Compound Content

Silicon Dioxide

Al, CaO, Carbon Dioxide, Mg, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

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

Properties

Physical Properties

Hardness

76.8

1 7

👆🏻

Grain Size

Very fine-grained

Fine Grained

Fracture

Uneven

Streak

White

White, Greenish White or Grey

Porosity

Less Porous

Luster

Vitreous

Subvitreous to Dull

Compressive Strength

225.00 N/mm²189.00 N/mm²

0.15 450

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Cleavage

Toughness

1.1

2.1

Specific Gravity

2.5-2.82.75-2.92

0 8.4

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Transparency

Opaque

Density

2.11-2.36 g/cm³1.5-2.5 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

2.39 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Indonesia, Japan, Nepal, South Korea

India, Russia

Africa

Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania

South Africa

Europe

Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom

Iceland

Others

Deposits in Western Continents

North America

Mexico, USA

Canada, USA

South America

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

Brazil

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

All about Andesite and Picrite Properties

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