Lignite

Slate

Lignite and Slate

Lignite

Slate

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Definition

Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat

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

History

Origin

France

England

Discoverer

Unknown

Abraham Gottlob Werner

Etymology

From French, Latin lignum wood + -ite1

From Old French esclate, from esclat (French éclat)

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Amorphous, Glassy

Foliated

Color

Black, Brown, Dark Brown, Grey, Light to Dark Grey

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Veined or Pebbled

Dull

Uses

Architecture

Interior Uses

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

Exterior Uses

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

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Steel Production

As Dimension Stone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Electricity Generation

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

Types

Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite

Phyllite, Schist, and Slate

Features

Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Coal formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.

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

Composition

Mineral Content

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

Compound Content

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

13-4

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Conchoidal

Splintery

Streak

Black

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Dull to Vitreous to Submetallic

Dull

Compressive Strength

-30.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.2

Specific Gravity

1.1-1.42.65-2.8

0 8.4

👆🏻

Transparency

Opaque

Density

800-801 g/cm³2.6-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.26 kJ/Kg K0.76 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam

China, India, Turkey

Africa

Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania

Europe

Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom

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

Others

Arctic

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Brazil, Chile, Colombia, Venezuela

Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, Victoria

All about Lignite and Slate Properties

Know all about Lignite and Slate properties here. All properties of rocks are important as they define the type of rock and its application. Lignite belongs to Sedimentary Rocks while Slate belongs to Metamorphic Rocks.Texture of Lignite is Amorphous, Glassy whereas that of Slate is Foliated. Lignite appears Veined or Pebbled and Slate appears Dull. The luster of Lignite is dull to vitreous to submetallic while that of Slate is dull. Lignite is available in black, brown, dark brown, grey, light to dark grey colors whereas Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors. The commercial uses of Lignite are electricity generation and that 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.