Comendite

Schist

Comendite and Schist

Comendite

Schist

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Definition

Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation

History

Origin

Italy

Discoverer

Unknown

Etymology

Comendite derives its name from the area of Le Commende on San Pietro Island in Italy

From French schiste, Greek skhistos i.e. split

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Porphyritic

Foliated, Platy

Color

Blue, Bluish - Grey

Black, Blue, Brown, Dark Brown, Green, Grey, Silver

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Foliated

Layered and Shiny

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar

As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone

Medical Industry

Antiquity Uses

Artifacts

Other Uses

Commercial Uses

Cemetery Markers

Used in aquariums, Writing Slates

Types

Rhyolite

Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.

Features

Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock

Easily splits into thin plates, Smooth to touch

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Comendite is a type of Igneous rock which is formed due to cooling and solidification of lava or magma. It may form with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.

Composition

Mineral Content

Albite, Amphibole, Quartz

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc

Compound Content

Al, Fe, Potassium Oxide

CaO, Carbon Dioxide, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

6-73.5-4

1 7

👆🏻

Grain Size

Medium Grained

Medium to Fine Coarse Grained

Fracture

Pervasive

Conchoidal

Streak

Bluish Black

White

Porosity

Highly Porous

Luster

Dull

Shiny

Compressive Strength

92.40 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

Specific Gravity

2.382.5-2.9

0 8.4

👆🏻

Transparency

Opaque

Density

-9999 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.70 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Impact Resistant, Pressure Resistant, Water Resistant

Reserves

Deposits in Eastern Continents

Asia

China

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

Africa

East Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Europe

Italy

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

Others

Deposits in Western Continents

North America

Canada, Costa Rica, Cuba, Mexico, Panama, USA

South America

Brazil, Colombia, Guyana

Deposits in Oceania Continent

Australia

Queensland

New South Wales, New Zealand, Queensland

All about Comendite and Schist Properties

Know all about Comendite and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Comendite belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Comendite is Porphyritic whereas that of Schist is Foliated, Platy. Comendite appears Foliated and Schist appears Layered and Shiny. The luster of Comendite is dull while that of Schist is shiny. Comendite is available in blue, bluish - grey colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver colors. The commercial uses of Comendite are cemetery markers and that of Schist are used in aquariums, writing slates.