Hornfels

Skarn

Hornfels and Skarn

Hornfels

Skarn

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Definition

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

Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin

History

Origin

New Zealand

USA, Australia

Discoverer

Unknown

Tornebohm

Etymology

From German which means hornstone

From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Granular, Platy

Earthy, Mud-rich, Rough

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Roadstone

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)

Types

Biotite hornfels

Endoskarns

Features

Smooth to touch

Host Rock for Lead, Zinc and Copper Deposits

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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.

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

Composition

Mineral Content

Andalusite

Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite

Compound Content

Fe, Mg

Au, CaO, Carbon Dioxide, Cu, Fe, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

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

Properties

Physical Properties

Hardness

2-36.5

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Irregular

Streak

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Shiny

Waxy and Dull

Compressive Strength

5.80 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Slaty

Toughness

2.4

Specific Gravity

3.4-3.92.86

0 8.4

👆🏻

Transparency

Opaque

Density

0.25-0.30 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Russia, Saudi Arabia, South Korea, Sri Lanka

Africa

Cameroon, East Africa, Tanzania, Western Africa

South Africa, Western Africa

Europe

United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

Canada

South America

Bolivia, Brazil, Colombia, Ecuador

Brazil, Colombia, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

Central Australia, Western Australia

All about Hornfels and Skarn Properties

Know all about Hornfels and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels and Skarn belong to Metamorphic Rocks.Texture of Hornfels is Granular, Platy whereas that of Skarn is Earthy, Mud-rich, Rough. Hornfels appears Dull and Skarn appears Dull. The luster of Hornfels is shiny while that of Skarn is waxy and dull. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Skarn is available in black, brown, green, grey, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).