Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
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
Italy
New Zealand
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From Greek mulōn mill + -ite
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
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Foliated
Color
Blue, Bluish - Grey
Black to Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Foliated
Dull, Banded and Foilated
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
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
for Road Aggregate, Landscaping, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Monuments
Other Uses
Commercial Uses
Cemetery Markers
Creating Artwork, Gemstone, Jewelry
Types
Rhyolite
Blastomylonites, Ultramylonites and Phyllonites
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
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.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Composition
Mineral Content
Albite, Amphibole, Quartz
Porphyroblasts
Compound Content
Al, Fe, Potassium Oxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Physical Properties
Hardness
6-73-4
1
7
👆🏻
Grain Size
Medium Grained
Fine Grained
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
White
Porosity
Highly Porous
Highly Porous
Luster
Dull
Shiny
Compressive Strength
92.40 N/mm21.28 N/mm2
0.15
450
👆🏻
Cleavage
-
Conchoidal
Toughness
2
-
Specific Gravity
2.382.97-3.05
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
-9999 g/cm32.6-4.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.79 kJ/Kg K1.50 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China
China, India, Indonesia, Saudi Arabia, South Korea
Africa
East Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Italy
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Others
-
-
Deposits in Western Continents
North America
-
USA
South America
-
-
Deposits in Oceania Continent
Australia
Queensland
Central Australia, Western Australia