Felsite

Dacite

Felsite and Dacite

Felsite

Dacite

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Definition

Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition

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

History

Origin

Romania and Moldova, Europe

Discoverer

Unknown

Etymology

From English feldspar and -ite

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Arborescent Patterned, Vitreous

Aphanitic to Porphyritic

Color

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

Paving Stone, Garden Decoration

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

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

Medical Industry

Surgery

Antiquity Uses

Artifacts

Other Uses

Commercial Uses

Mirror, Jewelry

Commemorative Tablets, Creating Artwork

Types

Igneous rock

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock

Host Rock for Lead, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Felsite 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.

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.

Composition

Mineral Content

Feldspar, Iron Oxides

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

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Glacier Erosion, Water Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

5-5.52-2.25

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Subvitreous to Dull

Compressive Strength

0.15 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

2.6-2.72.86-2.87

0 8.4

👆🏻

Transparency

Translucent

Density

2.6 g/cm³2.77-2.771 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

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

Africa

Kenya

Europe

Greece, Hungary, Iceland, Italy, Turkey

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

USA

South America

Argentina, Chile, Ecuador, Peru

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

Deposits in Oceania Continent

Australia

New Zealand

New Zealand, South Australia, Western Australia

All about Felsite and Dacite Properties

Know all about Felsite and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Felsite and Dacite belong to Igneous Rocks.Texture of Felsite is Arborescent Patterned, Vitreous whereas that of Dacite is Aphanitic to Porphyritic. Felsite appears Layered, Banded, Veined and Shiny and Dacite appears Vesicular. The luster of Felsite is vitreous while that of Dacite is subvitreous to dull. Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Felsite are mirror, jewelry and that of Dacite are commemorative tablets, creating artwork.