Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks
History
Origin
Italy
USA
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From silica, the main mineral content of Jasperoid
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Earthy
Color
Blue, Bluish - Grey
Black, Brown, Green, Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Foliated
Glassy or Pearly
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building 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 a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
Other Uses
Commercial Uses
Cemetery Markers
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Rhyolite
-
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.
Composition
Mineral Content
Albite, Amphibole, Quartz
Clay Minerals, Pyrite, Quartz, Sulfides
Compound Content
Al, Fe, Potassium Oxide
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Water Erosion
-
Physical Properties
Hardness
6-73.5-4
1
7
👆🏻
Grain Size
Medium Grained
Medium to Fine Coarse Grained
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
White
Porosity
Highly Porous
Less Porous
Luster
Dull
Vitreous and Pearly
Compressive Strength
92.40 N/mm2140.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
2
1
Specific Gravity
2.382.8-3
0
8.4
👆🏻
Transparency
Opaque
Transparent to Translucent
Density
-9999 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.79 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China
China, India
Africa
East Africa
Morocco, Namibia
Europe
Italy
Austria, Italy, Romania, Spain, Switzerland
Others
-
-
Deposits in Western Continents
North America
-
Mexico, USA
South America
-
Brazil, Colombia
Deposits in Oceania Continent
Australia
Queensland
New South Wales, Queensland, Yorke Peninsula