Rhyodacite and Ignimbrite

Rhyodacite

Ignimbrite

Definition

Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite

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

History

Origin

USA

New Zealand

Discoverer

Unknown

Patrick Marshall

Etymology

Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Earthy

Aphanitic

Color

Black to Grey, Dark Greenish - Grey

Beige, Black, Brown, Grey, Pink, White

Maintenance

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Wind Resistant

Yes

Acid Resistant

Appearance

Skeletal

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Exterior Uses

As Building 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

Cemetery Markers, Creating Artwork

Cemetery Markers, Commemorative Tablets, Creating Artwork

Types

Not Available

Features

Available in Lots of Colors and Patterns

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

Rhyodacite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

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, NA, Potassium, Silicon Dioxide

Ca, NaCl

Transformation

Metamorphism

Yes

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional 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, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion

Properties

Physical Properties

Hardness

5.5-6

4-6

Grain Size

Fine Grained

Fracture

Conchoidal

Uneven

Streak

Black

White

Porosity

Less Porous

Highly Porous

Luster

Greasy to Dull

Vitreous to Dull

Compressive Strength

200.50 N/mm²

243.80 N/mm²

Cleavage

Not Available

Toughness

2.1

Not Available

Specific Gravity

2.34-2.40

2.73

Transparency

Opaque

Density

Not Available

1-1.8 g/cm³

Thermal Properties

Specific Heat Capacity

1.12 kJ/Kg K

0.20 kJ/Kg K

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

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

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

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

Europe

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland

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

Canada, USA

Canada, Costa Rica, Panama, USA

South America

Not Yet Found

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador

Deposits in Oceania Continent

Australia

Not Yet Found

Central Australia, Western Australia

Summary >>

<< Reserves

All about Rhyodacite and Ignimbrite Properties

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