Dacite and Ignimbrite

Dacite

Ignimbrite

Definition

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

Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows

History

Origin

Romania and Moldova, Europe

New Zealand

Discoverer

Unknown

Patrick Marshall

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 Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite

Class

Igneous 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

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Aphanitic

Color

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

Beige, Black, Brown, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Wind Resistant

Yes

Acid Resistant

Appearance

Vesicular

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Building houses or walls, Construction Aggregate

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts

Artifacts, Monuments, 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

Not Available

Features

Host Rock for Lead, Is one of the oldest rock

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Not Yet Used

Used

Famous Monuments

Not Applicable

Data Not Available

Sculpture

Not Yet Used

Used

Famous Sculptures

Not Applicable

Data Not Available

Pictographs

Used

Petroglyphs

Used

Figurines

Not Yet Used

Used

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.

Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.

Composition

Mineral Content

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

Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz

Compound Content

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

Ca, NaCl

Transformation

Metamorphism

Yes

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

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

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

Yes

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion

Properties

Physical Properties

Hardness

2-2.25

4-6

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Uneven

Streak

White

Porosity

Less Porous

Highly Porous

Luster

Subvitreous to Dull

Vitreous to Dull

Compressive Strength

Not Available

243.80 N/mm²

Cleavage

Perfect

Not Available

Toughness

Not Available

Specific Gravity

2.86-2.87

2.73

Transparency

Translucent

Opaque

Density

2.77-2.771 g/cm³

1-1.8 g/cm³

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K

0.20 kJ/Kg K

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Not Yet Found

Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen

Africa

Not Yet Found

Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda

Europe

France, Greece, Romania, Scotland, Spain

France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom

Others

Not Yet Found

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

USA

Canada, Costa Rica, Panama, USA

South America

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

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

Central Australia, Western Australia

Summary >>

<< Reserves

All about Dacite and Ignimbrite Properties

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