Arkose

Dacite

Arkose and Dacite

Arkose

Dacite

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Definition

Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar

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

History

Origin

France

Romania and Moldova, Europe

Discoverer

Alexandre Brongniart

Unknown

Etymology

From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones

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

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Clastic

Aphanitic to Porphyritic

Color

Reddish Brown

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Dull

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

Paving Stone, Office Buildings

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Whetstones

Curbing

Industry

Construction Industry

Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones

Commemorative Tablets, Creating Artwork

Types

Arkose

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.

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

Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz

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

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

6-72-2.25

1 7

👆🏻

Grain Size

Coarse Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

80.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

02.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

-9999 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.78 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

Africa

Namibia, Nigeria, South Africa

Europe

Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom

France, Greece, Romania, Scotland, Spain

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

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

Deposits in Oceania Continent

Australia

New South Wales, New Zealand

New Zealand, South Australia, Western Australia

All about Arkose and Dacite Properties

Know all about Arkose and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Arkose belongs to Sedimentary Rocks while Dacite belongs to Igneous Rocks.Texture of Arkose is Clastic whereas that of Dacite is Aphanitic to Porphyritic. Arkose appears Rough and Dull and Dacite appears Vesicular. The luster of Arkose is dull while that of Dacite is subvitreous to dull. Arkose is available in reddish brown colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Arkose are in aquifers, soil conditioner, source of magnesia (mgo), tombstones and that of Dacite are commemorative tablets, creating artwork.