Hornfels

Blueschist

Hornfels and Blueschist

Hornfels

Blueschist

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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

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

History

Origin

New Zealand

USA

Discoverer

Unknown

Edgar Bailey

Etymology

From German which means hornstone

From French schiste, Greek skhistos i.e. split

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Granular, Platy

Foliated

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Blue, Bluish - Grey, Purple, Shades of Blue

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Dull and Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Exterior Uses

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

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Roadstone

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Types

Biotite hornfels

Metamorphic rock

Features

Smooth to touch

Has High structural resistance against erosion and climate, Very fine grained 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.

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

Composition

Mineral Content

Andalusite

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

Compound Content

Fe, Mg

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

2-33.5-4

1 7

👆🏻

Grain Size

Fine Grained

Fine to Medium Grained

Fracture

Conchoidal

Streak

White to Grey

Porosity

Highly Porous

Luster

Shiny

Dull

Compressive Strength

5.80 N/mm²220.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Slaty

Toughness

1.5

Specific Gravity

3.4-3.93-3.2

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 K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Japan, Turkey

Africa

Cameroon, East Africa, Tanzania, Western Africa

Egypt, Ethiopia, South Africa

Europe

United Kingdom

France, Greece, Iceland

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Bolivia, Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

New Zealand

All about Hornfels and Blueschist Properties

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