Dacite

Rhomb Porphyry

Dacite and Rhomb Porphyry

Dacite

Rhomb Porphyry

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Definition

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

Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts

History

Origin

Romania and Moldova, Europe

Discoverer

Unknown

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 term that means purple

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

Color

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

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Rough

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)

Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Igneous rock

Features

Host Rock for Lead, Is one of the oldest rock

Host Rock for Lead

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.

Rhomb-porphyry 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.

Composition

Mineral Content

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

Alkali feldspar, Biotite, Plagioclase, Pyroxene

Compound Content

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

CaO, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion

Properties

Physical Properties

Hardness

2-2.255-5.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Streak

White

Porosity

Less Porous

Very Less Porous

Luster

Subvitreous to Dull

Compressive Strength

70.00 N/mm²310.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.7

Specific Gravity

2.86-2.872.86

0 8.4

👆🏻

Transparency

Translucent

Density

2.77-2.771 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

Africa

Europe

France, Greece, Romania, Scotland, Spain

Bulgaria

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

All about Dacite and Rhomb Porphyry Properties

Know all about Dacite and Rhomb Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Dacite and Rhomb Porphyry belong to Igneous Rocks.Texture of Dacite is Aphanitic to Porphyritic whereas that of Rhomb Porphyry is Aphanitic to Porphyritic. Dacite appears Vesicular and Rhomb Porphyry appears Rough. The luster of Dacite and Rhomb Porphyry is subvitreous to dull. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas Rhomb Porphyry is available in black, brown, green, grey, pink, white colors. The commercial uses of Dacite are commemorative tablets, creating artwork and that of Rhomb Porphyry are an oil and gas reservoir, as a feed additive for livestock, metallurgical flux, soil conditioner, source of magnesia (mgo).