Comendite

Rapakivi Granite

Comendite and Rapakivi Granite

Comendite

Rapakivi Granite

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Definition

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

Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase

History

Origin

Italy

Finland, Europe

Discoverer

Unknown

Jakob Sederholm

Etymology

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

From Finnish Rapakivi which stands for crumbly rock

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Porphyritic

Granular, Phaneritic

Color

Blue, Bluish - Grey

Black, Grey, Orange, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Foliated

Veined or Pebbled

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

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

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

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones

Types

Rhyolite

Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite

Features

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

Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock

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.

Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks

Composition

Mineral Content

Albite, Amphibole, Quartz

Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Compound Content

Al, Fe, Potassium Oxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6-76-7

1 7

👆🏻

Grain Size

Medium Grained

Large and Coarse Grained

Fracture

Pervasive

Streak

Bluish Black

White

Porosity

Highly Porous

Less Porous

Luster

Dull

Dull to Grainy with Sporadic parts Pearly and Vitreous

Compressive Strength

92.40 N/mm²175.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.382.6-2.7

0 8.4

👆🏻

Transparency

Opaque

Density

-9999 g/cm³2.6-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

East Africa

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

Europe

Italy

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic

Others

Deposits in Western Continents

North America

Canada, USA

South America

Deposits in Oceania Continent

Australia

Queensland

All about Comendite and Rapakivi Granite Properties

Know all about Comendite and Rapakivi Granite properties here. All properties of rocks are important as they define the type of rock and its application. Comendite and Rapakivi Granite belong to Igneous Rocks.Texture of Comendite is Porphyritic whereas that of Rapakivi Granite is Granular, Phaneritic. Comendite appears Foliated and Rapakivi Granite appears Veined or Pebbled. The luster of Comendite is dull while that of Rapakivi Granite is dull to grainy with sporadic parts pearly and vitreous. Comendite is available in blue, bluish - grey colors whereas Rapakivi Granite is available in black, grey, orange, pink, white colors. The commercial uses of Comendite are cemetery markers and that of Rapakivi Granite are cemetery markers, commemorative tablets, creating artwork, curling, laboratory bench tops, tombstones.