Dacite

Blueschist

Dacite and Blueschist

Dacite

Blueschist

Add ⊕

Definition

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

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

History

Origin

Romania and Moldova, Europe

USA

Discoverer

Unknown

Edgar Bailey

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 French schiste, Greek skhistos i.e. split

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Foliated

Color

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

Blue, Bluish - Grey, Purple, Shades of Blue

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Dull and Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Metamorphic rock

Features

Host Rock for Lead, Is one of the oldest rock

Has High structural resistance against erosion and climate, Very fine grained rock

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.

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

Composition

Mineral Content

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

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

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

Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

2-2.253.5-4

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine to Medium Grained

Fracture

Conchoidal

Streak

White

White to Grey

Porosity

Less Porous

Highly Porous

Luster

Subvitreous to Dull

Dull

Compressive Strength

70.00 N/mm²220.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Slaty

Toughness

1.5

Specific Gravity

2.86-2.873-3.2

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.77-2.771 g/cm³2.8-2.9 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

Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan, Turkey

Africa

Egypt, Ethiopia, South Africa

Europe

France, Greece, Romania, Scotland, Spain

France, Greece, Iceland

Others

Deposits in Western Continents

North America

USA

South America

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

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

New Zealand

All about Dacite and Blueschist Properties

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