Felsite

Variolite

Felsite and Variolite

Felsite

Variolite

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Definition

Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise 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

History

Origin

France

Discoverer

Unknown

Etymology

From English feldspar and -ite

From Latin varius, speckled, variegated

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

Texture

Arborescent Patterned, Vitreous

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Color

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

Black, Brown, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Exterior Uses

Paving Stone, Garden Decoration

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Surgery

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Mirror, Jewelry

Cemetery Markers, Creating Artwork

Types

Igneous rock

Metamorphic rock

Features

Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Felsite 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.

Composition

Mineral Content

Feldspar, Iron Oxides

Olivine, Plagioclase, Pyroxene

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, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Glacier Erosion, Water Erosion

Properties

Physical Properties

Hardness

5-5.56

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Streak

White

White to Grey

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Compressive Strength

0.15 N/mm²37.50 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.3

Specific Gravity

2.6-2.72.8-3

0 8.4

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Transparency

Translucent

Opaque

Density

2.6 g/cm³2.9-3.1 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

India, Russia

Africa

Kenya

South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

Iceland

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Brazil

Deposits in Oceania Continent

Australia

New Zealand

All about Felsite and Variolite Properties

Know all about Felsite and Variolite properties here. All properties of rocks are important as they define the type of rock and its application. Felsite and Variolite belong to Igneous Rocks.Texture of Felsite is Arborescent Patterned, Vitreous whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Felsite appears Layered, Banded, Veined and Shiny and Variolite appears Dull and Soft. The luster of Felsite is vitreous while that of Variolite is . Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Variolite is available in black, brown, light to dark grey colors. The commercial uses of Felsite are mirror, jewelry and that of Variolite are cemetery markers, creating artwork.