Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Origin
Italy
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From Adak, Aleutian Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Porphyritic
Color
Blue, Bluish - Grey
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Foliated
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
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
Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers
Commemorative Tablets, Pottery, Used in aquariums
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, Host rock for Diamond, 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.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Mineral Content
Albite, Amphibole, Quartz
Olivine, Plagioclase, Pyroxene
Compound Content
Al, Fe, Potassium Oxide
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Water Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Medium Grained
Fine to Medium Grained
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
Bluish Black
Porosity
Highly Porous
Less Porous
Luster
Dull
Grainy, Pearly and Vitreous
Compressive Strength
Not Available
Cleavage
Not Available
Not Available
Toughness
2
Not Available
Specific Gravity
2.38
Not Available
Transparency
Opaque
Opaque
Density
Not Available
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
East Africa
Ethiopia, Somalia, South Africa
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Not Yet Found
Canada, USA
South America
Not Yet Found
Brazil
Deposits in Oceania Continent
Australia
Queensland
Not Yet Found
Comendite vs Adakite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Comendite vs Adakite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Comendite and Properties of Adakite. Learn more about Comendite vs Adakite in the next section. The interior uses of Comendite include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Adakite include Decorative aggregates, Floor tiles, Homes, Hotels and Kitchens. Due to some exceptional properties of Comendite and Adakite, they have various applications in construction industry. The uses of Comendite in construction industry include Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar and that of Adakite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Comendite and Adakite
Here you can know more about Comendite and Adakite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Comendite and Adakite consists of mineral content and compound content. The mineral content of Comendite includes Albite, Amphibole, Quartz and mineral content of Adakite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all . When we have to compare Comendite vs Adakite, the texture, color and appearance plays an important role in determining the type of rock. Comendite is available in blue, bluish - grey colors whereas, Adakite is available in black, brown, light to dark grey colors. Appearance of Comendite is Foliated and that of Adakite is Dull and Soft. Properties of rock is another aspect for Comendite vs Adakite. The hardness of Comendite is 6-7 and that of Adakite is 3-4. The types of Comendite are Rhyolite whereas types of Adakite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Comendite and Adakite is bluish black. The specific heat capacity of Comendite is Not Available and that of Adakite is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Comendite is heat resistant, impact resistant whereas Adakite is heat resistant, pressure resistant, wear resistant.