Definition
Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Discoverer
Unknown
Unknown
Etymology
From Greek phullon leaf + -ite1
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phyllitic Sheen, Slaty
Earthy
Color
Black to Grey, Light Greenish Grey
Black to Grey, Dark Greenish - Grey
Durability
Durable
Durable
Appearance
Crinkled or Wavy
Skeletal
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building 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
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Artifacts, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Writing Slates
Cemetery Markers, Creating Artwork
Types
Phyllite
Intermediate volcanic rock
Features
Easily splits into thin plates, Is one of the oldest rock, Surfaces are often shiny
Available in Lots of Colors and Patterns
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.
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.
Mineral Content
Albite, Alusite, Amphibole, Apatite, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc, Zircon
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
CaO, Carbon Dioxide, MgO
Ca, Fe, Potassium Oxide, Potassium, Silicon Dioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact 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
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Phyllitic
Greasy to Dull
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.72-2.73
2.34-2.40
Transparency
Opaque
Opaque
Density
2.18-3.3 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Water Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, USA
South America
Brazil, Colombia, Guyana
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
-
Phyllite vs Rhyodacite 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. Phyllite vs Rhyodacite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Phyllite and Properties of Rhyodacite. Learn more about Phyllite vs Rhyodacite in the next section. The interior uses of Phyllite include Decorative aggregates, Floor tiles, Homes and Interior decoration whereas the interior uses of Rhyodacite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Phyllite and Rhyodacite, they have various applications in construction industry. The uses of Phyllite in construction industry include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Raw material for the manufacture of mortar, Roadstone and that of Rhyodacite include As dimension stone, Construction aggregate, For road aggregate, Landscaping.
More about Phyllite and Rhyodacite
Here you can know more about Phyllite and Rhyodacite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Phyllite and Rhyodacite consists of mineral content and compound content. The 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 and mineral content of Rhyodacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Metamorphic Rocks. When we have to compare Phyllite vs Rhyodacite, the texture, color and appearance plays an important role in determining the type of rock. Phyllite is available in black to grey, light greenish grey colors whereas, Rhyodacite is available in black to grey, dark greenish - grey colors. Appearance of Phyllite is Crinkled or Wavy and that of Rhyodacite is Skeletal. Properties of rock is another aspect for Phyllite vs Rhyodacite. The hardness of Phyllite is 1-2 and that of Rhyodacite is 5.5-6. The types of Phyllite are Phyllite whereas types of Rhyodacite are Intermediate volcanic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Phyllite is white while that of Rhyodacite is black. The specific heat capacity of Phyllite is 0.79 kJ/Kg K and that of Rhyodacite is 1.12 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Phyllite is heat resistant, pressure resistant, water resistant whereas Rhyodacite is heat resistant.