Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Discoverer
Unknown
Unknown
Etymology
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
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, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Granular
Porphyritic
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Blue, Bluish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded and Foilated
Foliated
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
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
Cemetery Markers, Creating Artwork
Cemetery Markers
Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Formation
Phonolite are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
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
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Albite, Amphibole, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Al, Fe, Potassium Oxide
Types of Metamorphism
Contact Metamorphism
Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Medium Grained
Fracture
Conchoidal to Uneven
Pervasive
Streak
White
Bluish Black
Porosity
Less Porous
Highly Porous
Luster
Greasy to Dull
Dull
Specific Gravity
2.6
2.38
Transparency
Translucent to Opaque
Opaque
Density
2.6 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
China
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
East Africa
Europe
Andorra, Finland, France, Germany, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Italy
Deposits in Western Continents
North America
Canada, USA
-
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
Queensland