Definition
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine
Discoverer
Unknown
Ferdinand von Hochstetter
Etymology
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
From the name of Dun Mountain, New Zealand, + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Earthy
Phaneritic
Color
Black to Grey, Dark Greenish - Grey
Dark Greenish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Rough and Shiny
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Intermediate volcanic rock
Dunite
Features
Available in Lots of Colors and Patterns
Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
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.
Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Ca, Fe, Potassium Oxide, Potassium, Silicon Dioxide
Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Less Porous
Less Porous
Luster
Greasy to Dull
Shiny
Specific Gravity
2.34-2.40
3-3.01
Transparency
Opaque
Translucent to Opaque
Density
-9999 g/cm3
2.84-2.85 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Morocco, South Africa
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
-
Argentina, Brazil, Colombia, Ecuador, Venezuela
Deposits in Oceania Continent
Australia
-
New Zealand, Western Australia
Rhyodacite vs Dunite 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 Dunite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rhyodacite and Properties of Dunite. Learn more about Rhyodacite vs Dunite in the next section. The interior uses of Rhyodacite include Decorative aggregates and Interior decoration whereas the interior uses of Dunite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Rhyodacite and Dunite, 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 Dunite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar.
More about Rhyodacite and Dunite
Here you can know more about Rhyodacite and Dunite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rhyodacite and Dunite 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 Dunite includes Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Rhyodacite vs Dunite, 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, Dunite is available in dark greenish - grey colors. Appearance of Rhyodacite is Skeletal and that of Dunite is Rough and Shiny. Properties of rock is another aspect for Rhyodacite vs Dunite. The hardness of Rhyodacite is 5.5-6 and that of Dunite is 3.5-4. The types of Rhyodacite are Intermediate volcanic rock whereas types of Dunite are Dunite. 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 Dunite is white. The specific heat capacity of Rhyodacite is 1.12 kJ/Kg K and that of Dunite is 1.25 kJ/Kg K. 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 Dunite is heat resistant, pressure resistant, wear resistant.