Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
Class
Igneous Rocks
Sedimentary 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, Opaque Rock
Texture
Porphyritic
Clastic, Splintery
Color
Blue, Bluish - Grey
Black, Brown, Buff, Green, Grey, Red, Yellow
Durability
Durable
Durable
Appearance
Foliated
Muddy
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Sculpture
Commercial Uses
Cemetery Markers
Creating Artwork, Pottery
Types
Rhyolite
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Jantar Mantar in India
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.
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
Mineral Content
Albite, Amphibole, Quartz
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Al, Fe, Potassium Oxide
Ca, Fe, Mg, Silicon Dioxide, Sodium
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium Grained
Very fine-grained
Fracture
Pervasive
Not Available
Streak
Bluish Black
White
Porosity
Highly Porous
Highly Porous
Cleavage
Not Available
Slaty
Specific Gravity
2.38
2.2-2.8
Transparency
Opaque
Opaque
Density
Not Available
2.4-2.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China
Bangladesh, China, India, Russia
Africa
East Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Italy
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Not Yet Found
USA
South America
Not Yet Found
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Queensland
New South Wales, New Zealand, Queensland, Victoria, Western Australia