Definition
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
  
Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks
  
History
  
  
Origin
USA
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
  
From Greek phullon leaf + -ite1
  
Class
Igneous Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Earthy
  
Phyllitic Sheen, Slaty
  
Color
Black to Grey, Dark Greenish - Grey
  
Black to Grey, Light Greenish Grey
  
Maintenance
More
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
No
  
Appearance
Skeletal
  
Crinkled or Wavy
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Garden Decoration
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Sculpture
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Creating Artwork
  
Cemetery Markers, Commemorative Tablets, Creating Artwork, Writing Slates
  
Types
Not Available
  
Not Available
  
Features
Available in Lots of Colors and Patterns
  
Easily splits into thin plates, Is one of the oldest rock, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Rhyodacite 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.
  
Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress.
  
Composition
  
  
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
  
Albite, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon
  
Compound Content
Ca, Fe, Potassium Oxide, NA, Potassium, Silicon Dioxide
  
CaO, Carbon Dioxide, MgO
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
5.5-6
  
1-2
  
Grain Size
Fine Grained
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Black
  
White
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Greasy to Dull
  
Phyllitic
  
Compressive Strength
200.50 N/mm
2
  
9
Not Available
  
Cleavage
Not Available
  
Crenulation and Pervasive
  
Toughness
2.1
  
1.2
  
Specific Gravity
2.34-2.40
  
2.72-2.73
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.18-3.3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
1.12 kJ/Kg K
  
7
Not Available
  
Resistance
Heat Resistant
  
Heat Resistant, Pressure Resistant, Water Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
  
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
  
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
Egypt, Ethiopia, Morocco, Nigeria, South Africa
  
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
  
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Costa Rica, Cuba, Mexico, Panama, USA
  
South America
Not Yet Found
  
Brazil, Colombia, Guyana
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New South Wales, New Zealand, Queensland
  
Rhyodacite vs Phyllite 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. Rhyodacite vs Phyllite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rhyodacite and Properties of Phyllite. Learn more about Rhyodacite vs Phyllite in the next section. The interior uses of Rhyodacite include Decorative aggregates and Interior decoration whereas the interior uses of Phyllite include Decorative aggregates, Floor tiles, Homes and Interior decoration. Due to some exceptional properties of Rhyodacite and Phyllite, they have various applications in construction industry. The uses of Rhyodacite in construction industry include As dimension stone, Construction aggregate, For road aggregate, Landscaping and that of Phyllite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Raw material for the manufacture of mortar, Roadstone.
More about Rhyodacite and Phyllite
Here you can know more about Rhyodacite and Phyllite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rhyodacite and Phyllite consists of mineral content and compound content. The mineral content of Rhyodacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon and mineral content of Phyllite includes Albite, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Rhyodacite vs Phyllite, the texture, color and appearance plays an important role in determining the type of rock. Rhyodacite is available in black to grey, dark greenish - grey colors whereas, Phyllite is available in black to grey, light greenish grey colors. Appearance of Rhyodacite is Skeletal and that of Phyllite is Crinkled or Wavy. Properties of rock is another aspect for Rhyodacite vs Phyllite. The hardness of Rhyodacite is 5.5-6 and that of Phyllite is 1-2. The types of Rhyodacite are Not Available whereas types of Phyllite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rhyodacite is black while that of Phyllite is white. The specific heat capacity of Rhyodacite is 1.12 kJ/Kg K and that of Phyllite is Not Available. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Rhyodacite is heat resistant whereas Phyllite is heat resistant, pressure resistant, water resistant.