Rhyodacite

Variolite

Rhyodacite and Variolite

Rhyodacite

Variolite

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1 Definition

1.1 Definition

Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite

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

1.2 History

1.2.1 Origin

USA

France

1.2.2 Discoverer

Unknown

1.3 Etymology

Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite

From Latin varius, speckled, variegated

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Earthy

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

2.2 Color

Black to Grey, Dark Greenish - Grey

Black, Brown, Light to Dark Grey

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

Skeletal

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

As Building Stone, Garden Decoration

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

4 Types

4.1 Types

Not Available

4.2 Features

Available in Lots of Colors and Patterns

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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Rhyodacite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

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

5.2 Composition

5.2.1 Mineral Content

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Olivine, Plagioclase, Pyroxene

5.2.2 Compound Content

Ca, Fe, Potassium Oxide, NA, Potassium, Silicon Dioxide

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

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

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5.5-66

1 7

6.1.2 Grain Size

Fine Grained

Not Applicable

6.1.3 Fracture

Conchoidal

6.1.4 Streak

Black

White to Grey

6.1.5 Porosity

Less Porous

6.1.6 Luster

Greasy to Dull

Not Available

6.1.7 Compressive Strength

200.50 N/mm²37.50 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

6.1.9 Toughness

2.1

2.3

6.1.10 Specific Gravity

2.34-2.402.8-3

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

Not Available2.9-3.1 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

1.12 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

India, Russia

7.1.2 Africa

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

South Africa

7.1.3 Europe

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland

Iceland

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

Not Yet Found

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

All about Rhyodacite and Variolite Properties

Know all about Rhyodacite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Rhyodacite and Variolite belong to Igneous Rocks.Texture of Rhyodacite is Earthy whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Rhyodacite appears Skeletal and Variolite appears Dull and Soft. The luster of Rhyodacite is greasy to dull while that of Variolite is not available. Rhyodacite is available in black to grey, dark greenish - grey colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Rhyodacite and Variolite are cemetery markers, creating artwork.