Definition
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
Discoverer
Unknown
Unknown
Etymology
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
From Latin term that means purple
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Aphanitic to Porphyritic
Color
Blue, Bluish - Grey
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Foliated
Rough
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving 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
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
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
Types
Rhyolite
Igneous rock
Features
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Host Rock for Lead
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.
Rhomb-porphyry is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Albite, Amphibole, Quartz
Alkali feldspar, Biotite, Plagioclase, Pyroxene
Compound Content
Al, Fe, Potassium Oxide
CaO, Cl, MgO
Types of Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Medium Grained
Fine Grained
Fracture
Pervasive
Conchoidal
Streak
Bluish Black
White
Porosity
Highly Porous
Very Less Porous
Luster
Dull
Subvitreous to Dull
Specific Gravity
2.38
2.86
Transparency
Opaque
Translucent
Density
-9999 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Deposits in Western Continents
Deposits in Oceania Continent
Comendite vs Rhomb Porphyry 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 Rhomb Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Comendite and Properties of Rhomb Porphyry. Learn more about Comendite vs Rhomb Porphyry in the next section. The interior uses of Comendite include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Rhomb Porphyry include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Comendite and Rhomb Porphyry, 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 Rhomb Porphyry include 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.
More about Comendite and Rhomb Porphyry
Here you can know more about Comendite and Rhomb Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Comendite and Rhomb Porphyry consists of mineral content and compound content. The mineral content of Comendite includes Albite, Amphibole, Quartz and mineral content of Rhomb Porphyry includes Alkali feldspar, Biotite, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Comendite vs Rhomb Porphyry, the texture, color and appearance plays an important role in determining the type of rock. Comendite is available in blue, bluish - grey colors whereas, Rhomb Porphyry is available in black, brown, green, grey, pink, white colors. Appearance of Comendite is Foliated and that of Rhomb Porphyry is Rough. Properties of rock is another aspect for Comendite vs Rhomb Porphyry. The hardness of Comendite is 6-7 and that of Rhomb Porphyry is 5-5.5. The types of Comendite are Rhyolite whereas types of Rhomb Porphyry are Igneous rock. 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 Rhomb Porphyry is white. The specific heat capacity of Comendite is 0.79 kJ/Kg K and that of Rhomb Porphyry is 0.92 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 Rhomb Porphyry is heat resistant, pressure resistant.