Syenite

Dacite

Syenite and Dacite

Syenite

Dacite

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Definition

Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

History

Origin

Romania and Moldova, Europe

Discoverer

Unknown

Etymology

From French syénite, from Latin Syenites (lapis ) (stone) of Syene

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Plutonic

Volcanic

Other Categories

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Earthy

Aphanitic to Porphyritic

Color

Brown, Buff, Cream, Green, Grey, Pink, White

Bluish - Grey, Brown, Grey, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded and Foilated

Vesicular

Uses

Architecture

Interior Uses

Flooring, Homes, Hotels, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Commemorative Tablets, Creating Artwork

Types

Shonkinite

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

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.

Composition

Mineral Content

Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

5.5-62-2.25

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Less Porous

Luster

Subvitreous to Dull

Compressive Strength

150.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

2.6-2.72.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.6-2.8 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

Bulgaria, England, Germany, Norway, Romania, Switzerland

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

USA

South America

Brazil, Chile

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Queensland, South Australia, Western Australia

New Zealand, South Australia, Western Australia

All about Syenite and Dacite Properties

Know all about Syenite and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Syenite and Dacite belong to Igneous Rocks.Texture of Syenite is Earthy whereas that of Dacite is Aphanitic to Porphyritic. Syenite appears Banded and Foilated and Dacite appears Vesicular. The luster of Syenite and Dacite is subvitreous to dull. Syenite is available in brown, buff, cream, green, grey, pink, white colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Syenite are cemetery markers, creating artwork and that of Dacite are commemorative tablets, creating artwork.