Definition
Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks
Comendite is a hard, peralkaline igneous rock, a type of light blue grey rhyolite
Discoverer
Unknown
Unknown
Etymology
From Greek phullon leaf + -ite1
Comendite derives its name from the area of Le Commende on San Pietro Island in Italy
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Phyllitic Sheen, Slaty
Porphyritic
Color
Black to Grey, Light Greenish Grey
Blue, Bluish - Grey
Durability
Durable
Durable
Appearance
Crinkled or Wavy
Foliated
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar, Roadstone
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, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Writing Slates
Cemetery Markers
Features
Easily splits into thin plates, Is one of the oldest rock, Surfaces are often shiny
Very fine grained rock, It is One of the Oldest, Strongest and Hardest Rock
Archaeological Significance
Formation
Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress.
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, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon
Albite, Amphibole, Quartz
Compound Content
CaO, Carbon Dioxide, MgO
Al, Fe, Potassium Oxide
Types of Metamorphism
-
Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Water Erosion
Grain Size
Medium to Fine Coarse Grained
Medium Grained
Fracture
Conchoidal
Pervasive
Streak
White
Bluish Black
Porosity
Highly Porous
Highly Porous
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.72-2.73
2.38
Transparency
Opaque
Opaque
Density
2.18-3.3 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Water Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
China
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
East Africa
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Italy
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
-
South America
Brazil, Colombia, Guyana
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
Queensland