Rhyolite

Pegmatite

Rhyolite and Pegmatite

Rhyolite

Pegmatite

Add ⊕

Definition

Rhyolite is a fine-grained igneous rock which is rich in silica

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

History

Origin

North America

Discoverer

Ferdinand von Richthofen

R. J. Hauy

Etymology

From German Rhyolit, from Greek rhuax lava stream + lithos stone

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Texture

Aphanitic, Glassy, Porphyritic

Pegmatitic

Color

Grey, White, Light Black

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives

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

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

Gemstone, Laboratory bench tops, Jewelry

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

Types

Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Features

Acidic in nature, Available in lots of colors

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.

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

Composition

Mineral Content

Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz

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

Compound Content

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

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional 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, Sea Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

6-77

1 7

👆🏻

Grain Size

Large and Coarse Grained

Medium to Coarse Grained

Fracture

Sub-conchoidal

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Earthy

Grainy, Pearly and Vitreous

Compressive Strength

140.00 N/mm²178.54 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

2.65-2.672.6-2.63

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.4-2.6 g/cm³2.6-2.65 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India

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

Africa

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

South Africa

Europe

Germany, Iceland, Ireland, Italy, Spain

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

Others

Deposits in Western Continents

North America

Canada, USA

Canada

South America

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

Brazil

Deposits in Oceania Continent

Australia

New Zealand, Queensland, Western Australia

New South Wales, Queensland, South Australia, Western Australia

All about Rhyolite and Pegmatite Properties

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