Felsite

Mylonite

Felsite and Mylonite

Felsite

Mylonite

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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

Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism

History

Origin

New Zealand

Discoverer

Unknown

Etymology

From English feldspar and -ite

From Greek mulōn mill + -ite

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Arborescent Patterned, Vitreous

Foliated

Color

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

Black to Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

Paving Stone, Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

for Road Aggregate, Landscaping, Roadstone

Medical Industry

Surgery

Antiquity Uses

Artifacts

Artifacts, Monuments

Other Uses

Commercial Uses

Mirror, Jewelry

Creating Artwork, Gemstone, Jewelry

Types

Igneous rock

Blastomylonites, Ultramylonites and Phyllonites

Features

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

Surfaces are often shiny

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.

Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.

Composition

Mineral Content

Feldspar, Iron Oxides

Porphyroblasts

Compound Content

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

Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Contact 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

Chemical Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

5-5.53-4

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Streak

White

Porosity

Very Less Porous

Highly Porous

Luster

Vitreous

Shiny

Compressive Strength

0.15 N/mm²1.28 N/mm²

0.15 450

👆🏻

Cleavage

Conchoidal

Toughness

Specific Gravity

2.6-2.72.97-3.05

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³2.6-4.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K1.50 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Indonesia, Saudi Arabia, South Korea

Africa

Kenya

Eritrea, Ethiopia, Ghana, South Africa, Western Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

England, Finland, France, Germany, Great Britain, Greece, United Kingdom

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

Central Australia, Western Australia

All about Felsite and Mylonite Properties

Know all about Felsite and Mylonite properties here. All properties of rocks are important as they define the type of rock and its application. Felsite belongs to Igneous Rocks while Mylonite belongs to Metamorphic Rocks.Texture of Felsite is Arborescent Patterned, Vitreous whereas that of Mylonite is Foliated. Felsite appears Layered, Banded, Veined and Shiny and Mylonite appears Dull, Banded and Foilated. The luster of Felsite is vitreous while that of Mylonite is shiny. Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Mylonite is available in black to grey colors. The commercial uses of Felsite are mirror, jewelry and that of Mylonite are creating artwork, gemstone, jewelry.