Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Origin
Hawaii Islands
Italy
Discoverer
Unknown
Unknown
Etymology
From Greek pikros bitter + -ite, 19th century
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Earthy, Rough
Porphyritic
Color
Black, Brown, Green, Grey, Pink, White, Yellow
Blue, Bluish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Shiny
Foliated
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Cemetery Markers
Features
Host Rock for Lead
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Formation
Picrite 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.
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.
Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Albite, Amphibole, Quartz
Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Al, Fe, Potassium Oxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Medium Grained
Fracture
Uneven
Pervasive
Streak
White, Greenish White or Grey
Bluish Black
Porosity
Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Specific Gravity
2.75-2.92
2.38
Transparency
Opaque
Opaque
Density
1.5-2.5 g/cm3
-9999 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Africa
South Africa
East Africa
Deposits in Western Continents
North America
Canada, USA
-
Deposits in Oceania Continent
All about Picrite and Comendite Properties
Know all about Picrite and Comendite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Comendite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Comendite is Porphyritic. Picrite appears Rough and Shiny and Comendite appears Foliated. The luster of Picrite is subvitreous to dull while that of Comendite is dull. Picrite is available in black, brown, green, grey, pink, white, yellow colors whereas Comendite is available in blue, bluish - grey colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Comendite are cemetery markers.