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
Medical Industry
Not Yet Used
Not Yet Used
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
Not Available
Not Available
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
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Figurines
Not Yet Used
Used
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, NA, 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
Cleavage
Not Available
Imperfect
Specific Gravity
2.34-2.40
3-3.01
Transparency
Opaque
Translucent to Opaque
Density
Not Available
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, Venezuela
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Not Yet Found
Argentina, Brazil, Colombia, Ecuador, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New Zealand, Western Australia