Variolite

Hornfels

Variolite vs Hornfels

Variolite

Hornfels

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1 Definition

1.1 Definition

Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance

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

1.2 History

1.2.1 Origin

France

New Zealand

1.2.2 Discoverer

Unknown

1.3 Etymology

From Latin varius, speckled, variegated

From German which means hornstone

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Granular, Platy

2.2 Color

Black, Brown, Light to Dark Grey

Brown, Dark Greenish - Grey, Green, Reddish Brown

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Dull and Soft

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Flooring, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Office Buildings

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

for Road Aggregate, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Not Available

Biotite hornfels

4.2 Features

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

Smooth to touch

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.

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.

5.2 Composition

5.2.1 Mineral Content

Olivine, Plagioclase, Pyroxene

Andalusite

5.2.2 Compound Content

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

Fe, Mg

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

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

Not Applicable

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Not Applicable

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

62-3

1 7

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White to Grey

Unknown

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Not Available

Shiny

6.1.7 Compressive Strength

37.50 N/mm²5.80 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Perfect

6.1.9 Toughness

2.3

Not Yet Found

6.1.10 Specific Gravity

2.8-33.4-3.9

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.9-3.1 g/cm³0.25-0.30 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.84 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

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

7.1.2 Africa

South Africa

Cameroon, East Africa, Tanzania, Western Africa

7.1.3 Europe

Iceland

United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

7.2.2 South America

Brazil

Bolivia, Brazil, Colombia, Ecuador

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New South Wales, New Zealand, Queensland, Western Australia

Variolite vs Hornfels Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Variolite and Hornfels Reserves. Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance. 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. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Variolite vs Hornfels information and Variolite vs Hornfels characteristics in the upcoming sections.

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Variolite vs Hornfels Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Variolite vs Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Hornfels. Learn more about Variolite vs Hornfels in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Variolite and Hornfels, they have various applications in construction industry. The uses of Variolite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Hornfels include For road aggregate, Roadstone.

More about Variolite and Hornfels

Here you can know more about Variolite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Hornfels consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Hornfels includes Andalusite. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Variolite is available in black, brown, light to dark grey colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Variolite is Dull and Soft and that of Hornfels is Dull. Properties of rock is another aspect for Variolite vs Hornfels. The hardness of Variolite is 6 and that of Hornfels is 2-3. The types of Variolite are Not Available whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite is white to grey while that of Hornfels is unknown. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Hornfels is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Variolite is heat resistant, pressure resistant, wear resistant whereas Hornfels is heat resistant, impact resistant, pressure resistant.