Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Discoverer
Unknown
Edgar Bailey
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
Group
Volcanic
Not Applicable
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Foliated
Color
Blue, Bluish - Grey
Blue, Bluish - Grey, Purple, Shades of Blue
Durability
Durable
Durable
Appearance
Foliated
Dull and Banded
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Not Yet Used
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, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Types
Rhyolite
Not Available
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Used
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.
Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.
Mineral Content
Albite, Amphibole, Quartz
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, 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
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Medium Grained
Fine to Medium Grained
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
White to Grey
Porosity
Highly Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Not Available
Slaty
Specific Gravity
2.38
3-3.2
Transparency
Opaque
Opaque
Density
Not Available
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Africa
East Africa
Egypt, Ethiopia, South Africa
Europe
Italy
France, Greece, Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Not Yet Found
USA
South America
Not Yet Found
Not Yet Found
Deposits in Oceania Continent
Australia
Queensland
New Zealand
All about Comendite and Blueschist Properties
Know all about Comendite and Blueschist properties here. All properties of rocks are important as they define the type of rock and its application. Comendite belongs to Igneous Rocks while Blueschist belongs to Metamorphic Rocks.Texture of Comendite is Porphyritic whereas that of Blueschist is Foliated. Comendite appears Foliated and Blueschist appears Dull and Banded. The luster of Comendite and Blueschist is dull. Comendite is available in blue, bluish - grey colors whereas Blueschist is available in blue, bluish - grey, purple, shades of blue colors. The commercial uses of Comendite are cemetery markers and that of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones.