Pegmatite

Tachylite

Pegmatite and Tachylite

Pegmatite

Tachylite

Add ⊕

Definition

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt

History

Origin

Iceland

Discoverer

R. J. Hauy

Unknown

Etymology

From Greek pegma, pegmat which means- thing joined together + -ite

From German Tachylite, from tachy- + Greek lutos soluble, melting

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Volcanic

Other Categories

Coarse Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Pegmatitic

Vitreous

Color

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow

Black, Dark Brown

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Glassy

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Cutting Tool, Knives, Landscaping, Scrapers

Medical Industry

Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Cemetery Markers, Creating Artwork

Types

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Volcanic glass

Features

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

Available in Lots of Colors and Patterns, Clasts are smooth to touch

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

Tachylite 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

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Feldspar, Olivine

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

Fe, Mg

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

75.5

1 7

👆🏻

Grain Size

Medium to Coarse Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Vermilion

Porosity

Less Porous

Luster

Grainy, Pearly and Vitreous

Resinous

Compressive Strength

178.54 N/mm²206.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

2.6-2.632.4

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.6-2.65 g/cm³3.058 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.56 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Cambodia, Russia, South Korea

Africa

South Africa

East Africa

Europe

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

England, Germany, Hungary, Iceland, Scotland, Sweden

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada

USA

South America

Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

Victoria

All about Pegmatite and Tachylite Properties

Know all about Pegmatite and Tachylite properties here. All properties of rocks are important as they define the type of rock and its application. Pegmatite and Tachylite belong to Igneous Rocks.Texture of Pegmatite is Pegmatitic whereas that of Tachylite is Vitreous. Pegmatite appears Layered, Banded, Veined and Shiny and Tachylite appears Glassy. The luster of Pegmatite is grainy, pearly and vitreous while that of Tachylite is resinous. Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors whereas Tachylite is available in black, dark brown colors. The commercial uses of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz and that of Tachylite are cemetery markers, creating artwork.