Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Banded, Rough
Color
Blue, Bluish - Grey
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Foliated
Glassy or Pearly
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, 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
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Cemetery Markers
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Rhyolite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Not Yet 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.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Albite, Amphibole, Quartz
Quartz, Silicon
Compound Content
Al, Fe, Potassium Oxide
Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion
Grain Size
Medium Grained
Very fine-grained
Fracture
Pervasive
Uneven, Splintery or Conchoidal
Streak
Bluish Black
White
Porosity
Highly Porous
Highly Porous
Luster
Dull
Waxy and Dull
Cleavage
Not Available
Non-Existent
Specific Gravity
2.38
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
Not Available
2.7 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
East Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Italy
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Not Yet Found
Canada, Mexico, USA
South America
Not Yet Found
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Queensland
New South Wales, Queensland, South Australia, Western Australia
Comendite vs Chert 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 Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Comendite and Properties of Chert. Learn more about Comendite vs Chert in the next section. The interior uses of Comendite include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Comendite and Chert, 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 Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Comendite and Chert
Here you can know more about Comendite and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Comendite and Chert consists of mineral content and compound content. The mineral content of Comendite includes Albite, Amphibole, Quartz and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Igneous Rocks. When we have to compare Comendite vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Comendite is available in blue, bluish - grey colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Comendite is Foliated and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Comendite vs Chert. The hardness of Comendite is 6-7 and that of Chert is 6.5-7. The types of Comendite are Rhyolite whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Comendite is bluish black while that of Chert is white. The specific heat capacity of Comendite is Not Available and that of Chert is 0.74 kJ/Kg K. 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 Chert is heat resistant, impact resistant, pressure resistant, wear resistant.