Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From German Grauwacke, from grau grey + wacke
Class
Igneous Rocks
Sedimentary 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
Clastic
Color
Blue, Bluish - Grey
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
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
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts
Artifacts, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
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.
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
Mineral Content
Albite, Amphibole, Quartz
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Al, Fe, Potassium Oxide
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Coastal Erosion, Water Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Grain Size
Medium Grained
Angular and Fine
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
White
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.38
2.2-2.8
Transparency
Opaque
Opaque
Density
-9999 g/cm3
2.6-2.61 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
East Africa
Namibia, Nigeria, South Africa
Europe
Italy
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
-
Canada, USA
Deposits in Oceania Continent
Australia
Queensland
New South Wales, New Zealand
All about Comendite and Greywacke Properties
Know all about Comendite and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Comendite belongs to Igneous Rocks while Greywacke belongs to Sedimentary Rocks.Texture of Comendite is Porphyritic whereas that of Greywacke is Clastic. Comendite appears Foliated and Greywacke appears Dull. The luster of Comendite and Greywacke is dull. Comendite is available in blue, bluish - grey colors whereas Greywacke is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Comendite are cemetery markers and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.