Rhyolite

Variolite

Rhyolite and Variolite

Rhyolite

Variolite

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1 Definition

1.1 Definition

Rhyolite is a fine-grained igneous rock which is rich in silica

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

North America

France

1.2.2 Discoverer

Ferdinand von Richthofen

Unknown

1.3 Etymology

From German Rhyolit, from Greek rhuax lava stream + lithos stone

From Latin varius, speckled, variegated

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Aphanitic, Glassy, Porphyritic

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

2.2 Color

Grey, White, Light Black

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

Banded

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens

Floor Tiles, Flooring, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

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

Garden Decoration, Office Buildings

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives

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

Gemstone, Laboratory bench tops, Jewelry

Cemetery Markers, Creating Artwork

4 Types

4.1 Types

Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.

Not Available

4.2 Features

Acidic in nature, Available in lots of colors

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

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.

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

Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz

Olivine, Plagioclase, Pyroxene

5.2.2 Compound Content

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium

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, Regional 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, Sea Erosion, Water Erosion, Wind Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-76

1 7

6.1.2 Grain Size

Large and Coarse Grained

Not Applicable

6.1.3 Fracture

Sub-conchoidal

Conchoidal

6.1.4 Streak

Colorless

White to Grey

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Earthy

Not Available

6.1.7 Compressive Strength

140.00 N/mm²37.50 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

6.1.9 Toughness

2.3

6.1.10 Specific Gravity

2.65-2.672.8-3

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.4-2.6 g/cm³2.9-3.1 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India

India, Russia

7.1.2 Africa

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

South Africa

7.1.3 Europe

Germany, Iceland, Ireland, Italy, Spain

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

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, Queensland, Western Australia

Not Yet Found

All about Rhyolite and Variolite Properties

Know all about Rhyolite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite and Variolite belong to Igneous Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Rhyolite appears Banded and Variolite appears Dull and Soft. The luster of Rhyolite is earthy while that of Variolite is not available. Rhyolite is available in grey, white, light black colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Variolite are cemetery markers, creating artwork.