Variolite

Phonolite

Variolite and Phonolite

Variolite

Phonolite

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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

Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic

History

Origin

France

Discoverer

Unknown

Etymology

From Latin varius, speckled, variegated

From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Granular

Color

Black, Brown, Light to Dark Grey

Brown, Buff, Cream, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Banded and Foilated

Uses

Architecture

Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Countertops, Decorative Aggregates, Flooring, Homes

Exterior Uses

Garden Decoration, Office Buildings

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Types

Metamorphic rock

Kenyte

Features

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

Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Phonolite are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite

Compound Content

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

65.5-6

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Conchoidal to Uneven

Streak

White to Grey

White

Porosity

Less Porous

Luster

Greasy to Dull

Compressive Strength

37.50 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.3

Specific Gravity

2.8-32.6

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.9-3.1 g/cm³2.6 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, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam

Africa

South Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

Iceland

Andorra, Finland, France, Germany, Great Britain, Italy, Norway, Portugal, Spain, Sweden

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Brazil, Chile, Colombia, Uruguay, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Queensland, South Australia, Tasmania, Western Australia

All about Variolite and Phonolite Properties

Know all about Variolite and Phonolite properties here. All properties of rocks are important as they define the type of rock and its application. Variolite and Phonolite belong to Igneous Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Phonolite is Granular. Variolite appears Dull and Soft and Phonolite appears Banded and Foilated. The luster of Variolite is while that of Phonolite is greasy to dull. Variolite is available in black, brown, light to dark grey colors whereas Phonolite is available in brown, buff, cream, green, grey, pink, white colors. The commercial uses of Variolite and Phonolite are cemetery markers, creating artwork.