Rhyolite

Scoria

Rhyolite and Scoria

Rhyolite

Scoria

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Definition

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

Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities

History

Origin

North America

Discoverer

Ferdinand von Richthofen

Unknown

Etymology

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

From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Aphanitic, Glassy, Porphyritic

Vesicular

Color

Grey, White, Light Black

Black, Brown, Dark Grey to Black, Red

Maintenance

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded

Glassy and Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Garden Decoration, 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

Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Gemstone, Laboratory bench tops, Jewelry

As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills

Types

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

Basaltic Scoria and Andesitic Scoria

Features

Acidic in nature, Available in lots of colors

Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny

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.

Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.

Composition

Mineral Content

Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz

Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica

Compound Content

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

Ca, NaCl

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact 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

Properties

Physical Properties

Hardness

6-75-6

1 7

👆🏻

Grain Size

Large and Coarse Grained

Fine Grained

Fracture

Sub-conchoidal

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Earthy

Subvitreous to Dull

Compressive Strength

140.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

2.65-2.67-9999

0 8.4

👆🏻

Transparency

Opaque

Density

2.4-2.6 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India

Afghanistan, Indonesia, Japan, Russia

Africa

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

Ethiopia, Kenya, Tanzania

Europe

Germany, Iceland, Ireland, Italy, Spain

Greece, Hungary, Iceland, Italy, Turkey

Others

Deposits in Western Continents

North America

Canada, USA

Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA

South America

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

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand, Queensland, Western Australia

New Zealand, Western Australia

All about Rhyolite and Scoria Properties

Know all about Rhyolite and Scoria properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite and Scoria belong to Igneous Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Scoria is Vesicular. Rhyolite appears Banded and Scoria appears Glassy and Vesicular. The luster of Rhyolite is earthy while that of Scoria is subvitreous to dull. Rhyolite is available in grey, white, light black colors whereas Scoria is available in black, brown, dark grey to black, red colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Scoria are as a traction material on snow-covered roads, creating artwork, high-temperature insulation, in gas barbecue grills.