Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz
Origin
Romania and Moldova, Europe
-
Discoverer
Unknown
Unknown
Etymology
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
From origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Granular
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Vesicular
Banded and Foilated
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, Paving 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, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Borolanite and Litchfieldite
Features
Host Rock for Lead, Is one of the oldest rock
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Archaeological Significance
Formation
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal to Uneven
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Greasy to Dull
Specific Gravity
2.86-2.87
2.6
Transparency
Translucent
Translucent to Opaque
Density
2.77-2.771 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Africa
-
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
France, Greece, Romania, Scotland, Spain
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Deposits in Western Continents
North America
USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Chile, Colombia, Uruguay, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
Dacite vs Nepheline Syenite 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. Dacite vs Nepheline Syenite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Dacite and Properties of Nepheline Syenite. Learn more about Dacite vs Nepheline Syenite in the next section. The interior uses of Dacite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Nepheline Syenite include Countertops, Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Dacite and Nepheline Syenite, they have various applications in construction industry. The uses of Dacite in construction industry include As dimension stone, Construction aggregate, For road aggregate, Landscaping and that of Nepheline Syenite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Landscaping, Making natural cement, Manufacture of magnesium and dolomite refractories, Production of glass and ceramics.
More about Dacite and Nepheline Syenite
Here you can know more about Dacite and Nepheline Syenite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Dacite and Nepheline Syenite consists of mineral content and compound content. The mineral content of Dacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon and mineral content of Nepheline Syenite includes Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite. You can also check out the list of all Igneous Rocks. When we have to compare Dacite vs Nepheline Syenite, the texture, color and appearance plays an important role in determining the type of rock. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas, Nepheline Syenite is available in brown, buff, cream, green, grey, pink, white colors. Appearance of Dacite is Vesicular and that of Nepheline Syenite is Banded and Foilated. Properties of rock is another aspect for Dacite vs Nepheline Syenite. The hardness of Dacite is 2-2.25 and that of Nepheline Syenite is 5.5-6. The types of Dacite are Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite whereas types of Nepheline Syenite are Borolanite and Litchfieldite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Dacite and Nepheline Syenite is white. The specific heat capacity of Dacite is 0.92 kJ/Kg K and that of Nepheline Syenite is 0.71 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Dacite is heat resistant, impact resistant, pressure resistant, wear resistant whereas Nepheline Syenite is heat resistant, impact resistant, wear resistant.