Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Quench
Color
Blue, Bluish - Grey
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration
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
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Cemetery Markers
Creating Artwork, Gemstone
Types
Rhyolite
Cataclastic rock
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Host Rock for Lead
Archaeological Significance
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Albite, Amphibole, Quartz
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Al, Fe, Potassium Oxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Coastal Erosion, Water Erosion
-
Grain Size
Medium Grained
Very fine-grained
Fracture
Pervasive
Uneven
Streak
Bluish Black
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
2.38
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
-9999 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Africa
East Africa
Western Africa
Europe
Italy
Great Britain, Switzerland
Deposits in Western Continents
Deposits in Oceania Continent
Australia
Queensland
Central Australia, Western Australia
All about Comendite and Pseudotachylite Properties
Know all about Comendite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Comendite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Comendite is Porphyritic whereas that of Pseudotachylite is Quench. Comendite appears Foliated and Pseudotachylite appears Dull and Soft. The luster of Comendite is dull while that of Pseudotachylite is vitreous. Comendite is available in blue, bluish - grey colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Comendite are cemetery markers and that of Pseudotachylite are creating artwork, gemstone.