Lignite

Hornfels

Lignite and Hornfels

Lignite

Hornfels

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Definition

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

Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock

History

Origin

France

New Zealand

Discoverer

Unknown

Etymology

From French, Latin lignum wood + -ite1

From German which means hornstone

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Family

Group

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Amorphous, Glassy

Granular, Platy

Color

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

Brown, Dark Greenish - Grey, Green, Reddish Brown

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Veined or Pebbled

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

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

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Steel Production

for Road Aggregate, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments

Other Uses

Commercial Uses

Electricity Generation

Cemetery Markers, Commemorative Tablets, Creating Artwork

Types

Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite

Biotite hornfels

Features

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

Smooth to touch

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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

Composition

Mineral Content

Andalusite

Compound Content

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

Fe, Mg

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

12-3

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Streak

Black

Porosity

Highly Porous

Luster

Dull to Vitreous to Submetallic

Shiny

Compressive Strength

-5.80 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

1.1-1.43.4-3.9

0 8.4

👆🏻

Transparency

Opaque

Density

800-801 g/cm³0.25-0.30 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.26 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand

Africa

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

Cameroon, East Africa, Tanzania, Western Africa

Europe

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

United Kingdom

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Brazil, Chile, Colombia, Venezuela

Bolivia, Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, Queensland, Victoria

New South Wales, New Zealand, Queensland, Western Australia

All about Lignite and Hornfels Properties

Know all about Lignite and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Lignite belongs to Sedimentary Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Lignite is Amorphous, Glassy whereas that of Hornfels is Granular, Platy. Lignite appears Veined or Pebbled and Hornfels appears Dull. The luster of Lignite is dull to vitreous to submetallic while that of Hornfels is shiny. Lignite is available in black, brown, dark brown, grey, light to dark grey colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Lignite are electricity generation and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.