Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
  
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
  
History
  
  
Origin
Unknown
  
Italy
  
Discoverer
Unknown
  
Unknown
  
Etymology
From French schiste, Greek skhistos i.e. split
  
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Medium Grained Rock, Opaque Rock
  
Texture
Foliated, Platy
  
Porphyritic
  
Color
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
  
Blue, Bluish - Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
Yes
  
Appearance
Layered and Shiny
  
Foliated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Interior Decoration
  
Countertops, Decorative Aggregates, Interior Decoration
  
Exterior Uses
Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Garden Decoration
  
Other Architectural Uses
Not Yet Used
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
  
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Used in aquariums, Writing Slates
  
Cemetery Markers
  
Types
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
  
Rhyolite
  
Features
Easily splits into thin plates, Smooth to touch
  
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Not Yet Used
  
Not Yet Used
  
Famous Sculptures
Not Applicable
  
Not Applicable
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Not Yet Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
  
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.
  
Composition
  
  
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
  
Albite, Amphibole, Quartz
  
Compound Content
CaO, Carbon Dioxide, MgO
  
Al, Fe, Potassium Oxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Cataclastic Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Coastal Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
3.5-4
  
6-7
  
Grain Size
Medium to Fine Coarse Grained
  
Medium Grained
  
Fracture
Conchoidal
  
Pervasive
  
Streak
White
  
Bluish Black
  
Porosity
Highly Porous
  
Highly Porous
  
Luster
Shiny
  
Dull
  
Compressive Strength
Not Available
  
92.40 N/mm
2
  
21
Cleavage
Slaty
  
Not Available
  
Toughness
1.5
  
2
  
Specific Gravity
2.5-2.9
  
2.38
  
Transparency
Opaque
  
Opaque
  
Density
2.8-2.9 g/cm3
  
Not Available
  
Thermal Properties
  
  
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
  
China
  
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
  
East Africa
  
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
  
Italy
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
  
Not Yet Found
  
South America
Brazil, Colombia, Guyana
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Queensland
  
Queensland
  
Schist vs Comendite 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. Schist vs Comendite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Schist and Properties of Comendite. Learn more about Schist vs Comendite in the next section. The interior uses of Schist include Decorative aggregates, Floor tiles and Interior decoration whereas the interior uses of Comendite include Countertops, Decorative aggregates and Interior decoration. Due to some exceptional properties of Schist and Comendite, they have various applications in construction industry. The uses of Schist in construction industry include As dimension stone, Building houses or walls, Cement manufacture, For road aggregate, Roadstone and that of Comendite include Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar.
More about Schist and Comendite
Here you can know more about Schist and Comendite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Schist and Comendite consists of mineral content and compound content. The mineral content of Schist includes Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc and mineral content of Comendite includes Albite, Amphibole, Quartz. You can also check out the list of all Metamorphic Rocks. When we have to compare Schist vs Comendite, the texture, color and appearance plays an important role in determining the type of rock. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas, Comendite is available in blue, bluish - grey colors. Appearance of Schist is Layered and Shiny and that of Comendite is Foliated. Properties of rock is another aspect for Schist vs Comendite. The hardness of Schist is 3.5-4 and that of Comendite is 6-7. The types of Schist are Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist. whereas types of Comendite are Rhyolite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Schist is white while that of Comendite is bluish black. The specific heat capacity of Schist is Not Available and that of Comendite is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Schist is impact resistant, pressure resistant, water resistant whereas Comendite is heat resistant, impact resistant.