Variolite

Porphyry

Variolite and Porphyry

Variolite

Porphyry

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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

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

1.2 History

1.2.1 Origin

France

Egypt

1.2.2 Discoverer

Unknown

1.3 Etymology

From Latin varius, speckled, variegated

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

Plutonic

1.6 Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Porphyritic

2.2 Color

Black, Brown, Light to Dark Grey

Black, Brown, Colourless, Green, Grey, Red, Rust, White

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.5.2 Wind Resistant

✔ ✘

2.5.3 Acid Resistant

✔ ✘

2.6 Appearance

Dull and Soft

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Office Buildings

Garden Decoration, 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

Construction Aggregate

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork, Gemstone, Jewelry

4 Types

4.1 Types

Not Available

Rhomb Porphyry

4.2 Features

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

Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

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.

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

5.2 Composition

5.2.1 Mineral Content

Olivine, Plagioclase, Pyroxene

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

5.2.2 Compound Content

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

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, 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

Biological Weathering, Chemical Weathering, Not Registered

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Not Applicable

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

66-7

1 7

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

Irregular

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Not Available

Dull

6.1.7 Compressive Strength

37.50 N/mm²NA

0.15 450

6.1.8 Cleavage

Not Available

Imperfect

6.1.9 Toughness

2.3

1.7

6.1.10 Specific Gravity

2.8-32.5-4

0 8.4

7.3.2 Transparency

Opaque

Translucent to Opaque

7.3.3 Density

2.9-3.1 g/cm³2.5-2.52 g/cm³

0 1400

7.4 Thermal Properties

7.4.1 Specific Heat Capacity

0.84 kJ/Kg KNA

0.14 3.2

7.4.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

8 Reserves

8.1 Deposits in Eastern Continents

8.1.1 Asia

India, Russia

China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

8.1.2 Africa

South Africa

Egypt, Ethiopia, Ghana, South Africa

8.1.3 Europe

Iceland

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

8.1.4 Others

Not Yet Found

Greenland

8.2 Deposits in Western Continents

8.2.1 North America

Canada, USA

Canada, Cuba, Jamaica, USA

8.2.2 South America

Brazil

Bolivia, Brazil, Colombia, Ecuador, Paraguay

8.3 Deposits in Oceania Continent

8.3.1 Australia

Not Yet Found

New South Wales, New Zealand, Western Australia

All about Variolite and Porphyry Properties

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