Slate

Pegmatite

Slate and Pegmatite

Slate

Pegmatite

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Definition

Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

History

Origin

England

Discoverer

Abraham Gottlob Werner

R. J. Hauy

Etymology

From Old French esclate, from esclat (French éclat)

From Greek pegma, pegmat which means- thing joined together + -ite

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Foliated

Pegmatitic

Color

Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone

As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Types

Phyllite, Schist, and Slate

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Features

Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

Composition

Mineral Content

Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

3-47

1 7

👆🏻

Grain Size

Very fine-grained

Medium to Coarse Grained

Fracture

Splintery

Conchoidal

Streak

Light to dark brown

White

Porosity

Less Porous

Luster

Dull

Grainy, Pearly and Vitreous

Compressive Strength

30.00 N/mm²178.54 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Perfect

Toughness

1.2

2.1

Specific Gravity

2.65-2.82.6-2.63

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.6-2.8 g/cm³2.6-2.65 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.76 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Turkey

China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Africa

South Africa

Europe

Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

Others

Arctic

Deposits in Western Continents

North America

USA

Canada

South America

Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

All about Slate and Pegmatite Properties

Know all about Slate and Pegmatite properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Pegmatite belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Pegmatite is Pegmatitic. Slate appears Dull and Pegmatite appears Layered, Banded, Veined and Shiny. The luster of Slate is dull while that of Pegmatite is grainy, pearly and vitreous. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates and that of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz.