Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
  
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
  
History
  
  
Origin
Italy
  
Germany
  
Discoverer
Unknown
  
Christian Leopold von Buch
  
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
  
From Latin glaber bare, smooth, bald
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Opaque Rock
  
Texture
Porphyritic
  
Phaneritic
  
Color
Blue, Bluish - Grey
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Foliated
  
Veined and Shiny
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
  
Countertops, Decorative Aggregates, 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
  
Industry
  
  
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, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Cemetery Markers
  
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
Types
Rhyolite
  
Not Available
  
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
  
Smooth to touch
  
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
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
  
Composition
  
  
Mineral Content
Albite, Amphibole, Quartz
  
Augite, Olivine, Plagioclase, Pyroxene
  
Compound Content
Al, Fe, Potassium Oxide
  
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Chemical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Water Erosion
  
Coastal Erosion
  
Physical Properties
  
  
Hardness
6-7
  
7
  
Grain Size
Medium Grained
  
Coarse Grained
  
Fracture
Pervasive
  
Conchoidal
  
Streak
Bluish Black
  
Black
  
Porosity
Highly Porous
  
Highly Porous
  
Luster
Dull
  
Not Available
  
Compressive Strength
92.40 N/mm2
  
21
225.00 N/mm2
  
7
Cleavage
Not Available
  
Not Available
  
Toughness
2
  
1.6
  
Specific Gravity
2.38
  
2.86-2.87
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.7-3.3 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Impact Resistant
  
Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China
  
India, Russia
  
Africa
East Africa
  
South Africa
  
Europe
Italy
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Not Yet Found
  
Canada, USA
  
South America
Not Yet Found
  
Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Queensland
  
New Zealand, Queensland