Variolite

Trachyte

Variolite and Trachyte

Variolite

Trachyte

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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

Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar

History

Origin

France

Discoverer

Unknown

Alexandre Brongniart and René Just Haüy

Etymology

From Latin varius, speckled, variegated

From Greek trakhus rough’ or trakhutēs roughness

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

Aphanitic to Porphyritic

Color

Black, Brown, Light to Dark Grey

Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Banded

Uses

Architecture

Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Office Buildings

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Types

Metamorphic rock

Felsic volcanic rock

Features

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

Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable

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.

Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz

Compound Content

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

Potassium Oxide, Sodium Oxide, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Properties

Physical Properties

Hardness

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Streak

White to Grey

White

Porosity

Less Porous

Luster

Metallic

Compressive Strength

37.50 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.3

Specific Gravity

2.8-32.7

0 8.4

👆🏻

Transparency

Opaque

Density

2.9-3.1 g/cm³2.43-2.45 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

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

South Africa

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

Europe

Iceland

Bulgaria, England, Germany, Norway, Romania, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

Brazil, Chile

Deposits in Oceania Continent

Australia

New Zealand, Queensland, South Australia, Western Australia

All about Variolite and Trachyte Properties

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