Picrite

Schist

Picrite and Schist

Picrite

Schist

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Definition

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

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation

History

Origin

Hawaii Islands

Discoverer

Unknown

Etymology

From Greek pikros bitter + -ite, 19th century

From French schiste, Greek skhistos i.e. split

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness 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

Foliated, Platy

Color

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

Black, Blue, Brown, Dark Brown, Green, Grey, Silver

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Layered and Shiny

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Floor Tiles, Interior Decoration

Exterior Uses

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

Garden Decoration, Paving Stone

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.

As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts

Other Uses

Commercial Uses

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

Used in aquariums, Writing Slates

Types

Oceanite

Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.

Features

Host Rock for Lead

Easily splits into thin plates, Smooth to touch

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.

Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.

Composition

Mineral Content

Biotite, Olivine, Plagioclase, Pyrrhotite

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc

Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

CaO, Carbon Dioxide, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic 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

Properties

Physical Properties

Hardness

6.83.5-4

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Uneven

Conchoidal

Streak

White, Greenish White or Grey

White

Porosity

Less Porous

Highly Porous

Luster

Subvitreous to Dull

Shiny

Compressive Strength

189.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.1

1.5

Specific Gravity

2.75-2.922.5-2.9

0 8.4

👆🏻

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 K0.70 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Impact Resistant, Pressure Resistant, Water Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

Africa

South Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Europe

Iceland

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

Canada, Costa Rica, Cuba, Mexico, Panama, USA

South America

Brazil

Brazil, Colombia, Guyana

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

All about Picrite and Schist Properties

Know all about Picrite and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Picrite is Earthy, Rough whereas that of Schist is Foliated, Platy. Picrite appears Rough and Shiny and Schist appears Layered and Shiny. The luster of Picrite is subvitreous to dull while that of Schist is shiny. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver 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 Schist are used in aquariums, writing slates.