Hornfels

Jasperoid

Hornfels and Jasperoid

Hornfels

Jasperoid

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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

Jasperoid is a rare, peculiar type of metasomatic alteration of rocks

History

Origin

New Zealand

USA

Discoverer

Unknown

Etymology

From German which means hornstone

From silica, the main mineral content of Jasperoid

Class

Metamorphic Rocks

Sedimentary 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

Earthy

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Glassy or Pearly

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Exterior Uses

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

As Building Stone, Garden Decoration, Office Buildings, 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, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock

Medical Industry

Taken as a Supplement for Calcium or Magnesium

Antiquity Uses

Artifacts, Monuments

Artifacts, Jewellery, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)

Types

Biotite hornfels

Features

Smooth to touch

Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

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.

Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.

Composition

Mineral Content

Andalusite

Clay Minerals, Pyrite, Quartz, Sulfides

Compound Content

Fe, Mg

NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic 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

2-33.5-4

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Shiny

Vitreous and Pearly

Compressive Strength

5.80 N/mm²140.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

3.4-3.92.8-3

0 8.4

👆🏻

Transparency

Opaque

Transparent to Translucent

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, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India

Africa

Cameroon, East Africa, Tanzania, Western Africa

Morocco, Namibia

Europe

United Kingdom

Austria, Italy, Romania, Spain, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

Mexico, USA

South America

Bolivia, Brazil, Colombia, Ecuador

Brazil, Colombia

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

New South Wales, Queensland, Yorke Peninsula

All about Hornfels and Jasperoid Properties

Know all about Hornfels and Jasperoid properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Jasperoid belongs to Sedimentary Rocks.Texture of Hornfels is Granular, Platy whereas that of Jasperoid is Earthy. Hornfels appears Dull and Jasperoid appears Glassy or Pearly. The luster of Hornfels is shiny while that of Jasperoid is vitreous and pearly. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Jasperoid is available in black, brown, green, grey, pink, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Jasperoid are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).