Dacite

Hornfels

Dacite and Hornfels

Dacite

Hornfels

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1 Definition

1.1 Definition

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

Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock

1.2 History

1.2.1 Origin

Romania and Moldova, Europe

New Zealand

1.2.2 Discoverer

Unknown

1.3 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 German which means hornstone

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

Granular, Platy

2.2 Color

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

Brown, Dark Greenish - Grey, Green, Reddish Brown

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Metamorphic Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

42% Metamorphic Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

19% Metamorphic Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

15% Metamorphic Rocks Rocks have it !

2.5 Appearance

Vesicular

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

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

for Road Aggregate, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Commemorative Tablets, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Biotite hornfels

4.2 Features

Host Rock for Lead, Is one of the oldest rock

Smooth to touch

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

5.2 Composition

5.2.1 Mineral Content

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

Andalusite

5.2.2 Compound Content

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

Fe, Mg

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

50% Metamorphic Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

77% Metamorphic Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

2-2.25

2-3

6.1.2 Grain Size

Medium to Fine Coarse Grained

Fine Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

Unknown

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Subvitreous to Dull

Shiny

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

Not Available

Rank: N/A (Overall)▶

5.80 N/mm²

Rank: 31 (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Perfect

6.1.9 Toughness

Not Available

Not Yet Found

6.1.10 Specific Gravity

2.86-2.87

3.4-3.9

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.77-2.771 g/cm³

0.25-0.30 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.92 kJ/Kg K

Rank: 10 (Overall)▶

0.84 kJ/Kg K

Rank: 15 (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Not Yet Found

Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand

7.1.2 Africa

Not Yet Found

Cameroon, East Africa, Tanzania, Western Africa

7.1.3 Europe

France, Greece, Romania, Scotland, Spain

United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

USA

Canada, USA

7.2.2 South America

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

Bolivia, Brazil, Colombia, Ecuador

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, South Australia, Western Australia

New South Wales, New Zealand, Queensland, Western Australia

All about Dacite and Hornfels Properties

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