Hornfels

Migmatite

Hornfels and Migmatite

Hornfels

Migmatite

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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

Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components

History

Origin

New Zealand

Southern Alps, France

Discoverer

Unknown

Jakob Sederholm

Etymology

From German which means hornstone

From the Greek word migma which means a mixture

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

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

Texture

Granular, Platy

Foliated

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Countertops, Flooring, Kitchens

Exterior Uses

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

As Building Stone, As Facing Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Roadstone

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends

Types

Biotite hornfels

Diatexites and Metatexites

Features

Smooth to touch

Generally rough to touch, Is one of the oldest rock

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.

Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.

Composition

Mineral Content

Andalusite

Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon

Compound Content

Fe, Mg

Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

2-35.5-6.5

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Irregular

Streak

White

Porosity

Highly Porous

Very Less Porous

Luster

Shiny

Dull to Pearly to Subvitreous

Compressive Strength

5.80 N/mm²120.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.2

Specific Gravity

3.4-3.92.65-2.75

0 8.4

👆🏻

Transparency

Opaque

Density

0.25-0.30 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia

Africa

Cameroon, East Africa, Tanzania, Western Africa

Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo

Europe

United Kingdom

Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

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

South America

Bolivia, Brazil, Colombia, Ecuador

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

New South Wales, New Zealand, Queensland, Victoria

All about Hornfels and Migmatite Properties

Know all about Hornfels and Migmatite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels and Migmatite belong to Metamorphic Rocks.Texture of Hornfels is Granular, Platy whereas that of Migmatite is Foliated. Hornfels appears Dull and Migmatite appears Dull, Banded and Foilated. The luster of Hornfels is shiny while that of Migmatite is dull to pearly to subvitreous. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Migmatite is available in black, bluish - grey, brown, brown- black, dark greenish - grey, dark grey to black colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Migmatite are cemetery markers, jewelry, tombstones, used to manufracture paperweights and bookends.