Dacite

Amphibolite

Dacite and Amphibolite

Dacite

Amphibolite

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Definition

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

Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase

History

Origin

Romania and Moldova, Europe

Discoverer

Unknown

Alexandre Brongniart

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 Amphibole + -ite

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Banded, Foliated, Massive

Color

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

Black, Brown, Green, Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Foliated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork

Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Hornblendite

Features

Host Rock for Lead, Is one of the oldest rock

Clasts are smooth to touch, Matrix variable, Surfaces are often shiny

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.

Composition

Mineral Content

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

Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

2-2.256-7

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Medium to Coarse Grained

Fracture

Conchoidal

Irregular to Conchoidal

Streak

White

White to Grey

Porosity

Less Porous

Luster

Subvitreous to Dull

Vitreous to Dull

Compressive Strength

70.00 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.3

Specific Gravity

2.86-2.872.5

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.77-2.771 g/cm³2.85-3.07 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Russia, Turkey

Africa

Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda

Europe

France, Greece, Romania, Scotland, Spain

Germany, Greece, Iceland, Norway, Poland

Others

Deposits in Western Continents

North America

USA

Canada, USA

South America

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

Brazil

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

South Australia, Western Australia

All about Dacite and Amphibolite Properties

Know all about Dacite and Amphibolite properties here. All properties of rocks are important as they define the type of rock and its application. Dacite belongs to Igneous Rocks while Amphibolite belongs to Metamorphic Rocks.Texture of Dacite is Aphanitic to Porphyritic whereas that of Amphibolite is Banded, Foliated, Massive. Dacite appears Vesicular and Amphibolite appears Foliated. The luster of Dacite is subvitreous to dull while that of Amphibolite is vitreous to dull. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas Amphibolite is available in black, brown, green, grey colors. The commercial uses of Dacite are commemorative tablets, creating artwork and that of Amphibolite are cemetery markers, commemorative tablets, creating artwork.