Hornfels

Adakite

Hornfels and Adakite

Hornfels

Adakite

Add ⊕

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

Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs

History

Origin

New Zealand

Adak, Aleutian Islands

Discoverer

Unknown

Defant and Drummond

Etymology

From German which means hornstone

From Adak, Aleutian Islands

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Granular, Platy

Porphyritic

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Black, Brown, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens

Exterior Uses

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

As Building Stone, As Facing Stone, Office Buildings

Other Architectural Uses

Curbing

Whetstones

Industry

Construction Industry

for Road Aggregate, Roadstone

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Antiquity Uses

Artifacts, Monuments

Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

Commemorative Tablets, Pottery, Used in aquariums

Types

Biotite hornfels

Intermediate volcanic rock

Features

Smooth to touch

Has High structural resistance against erosion and climate, Host rock for Diamond, 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.

Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.

Composition

Mineral Content

Andalusite

Olivine, Plagioclase, Pyroxene

Compound Content

Fe, Mg

Aluminium Oxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Coastal Erosion, Sea Erosion, Water Erosion

Properties

Physical Properties

Hardness

2-33-4

1 7

👆🏻

Grain Size

Fine Grained

Fine to Medium Grained

Fracture

Conchoidal

Streak

Bluish Black

Porosity

Highly Porous

Less Porous

Luster

Shiny

Grainy, Pearly and Vitreous

Compressive Strength

5.80 N/mm²200.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

3.4-3.9-9999

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 K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India, Russia

Africa

Cameroon, East Africa, Tanzania, Western Africa

Ethiopia, Somalia, South Africa

Europe

United Kingdom

Iceland

Others

Deposits in Western Continents

North America

Canada, USA

South America

Bolivia, Brazil, Colombia, Ecuador

Brazil

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

All about Hornfels and Adakite Properties

Know all about Hornfels and Adakite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Adakite belongs to Igneous Rocks.Texture of Hornfels is Granular, Platy whereas that of Adakite is Porphyritic. Hornfels appears Dull and Adakite appears Dull and Soft. The luster of Hornfels is shiny while that of Adakite is grainy, pearly and vitreous. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Adakite is available in black, brown, light to dark grey colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Adakite are commemorative tablets, pottery, used in aquariums.