Hornfels

Scoria

Hornfels and Scoria

Hornfels

Scoria

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Definition

Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock

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

History

Origin

New Zealand

Discoverer

Unknown

Etymology

From German which means hornstone

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

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Granular, Platy

Vesicular

Color

Brown, Dark Greenish - Grey, Green, Reddish Brown

Black, Brown, Dark Grey to Black, Red

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Glassy and Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

for Road Aggregate, Roadstone

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

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork

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

Types

Biotite hornfels

Basaltic Scoria and Andesitic Scoria

Features

Smooth to touch

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

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

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

Composition

Mineral Content

Andalusite

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

Compound Content

Fe, Mg

Ca, NaCl

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

2-35-6

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Shiny

Subvitreous to Dull

Compressive Strength

5.80 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

Specific Gravity

3.4-3.9-9999

0 8.4

👆🏻

Transparency

Opaque

Density

0.25-0.30 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand

Afghanistan, Indonesia, Japan, Russia

Africa

Cameroon, East Africa, Tanzania, Western Africa

Ethiopia, Kenya, Tanzania

Europe

United Kingdom

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

Bolivia, Brazil, Colombia, Ecuador

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Western Australia

New Zealand, Western Australia

All about Hornfels and Scoria Properties

Know all about Hornfels and Scoria properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Scoria belongs to Igneous Rocks.Texture of Hornfels is Granular, Platy whereas that of Scoria is Vesicular. Hornfels appears Dull and Scoria appears Glassy and Vesicular. The luster of Hornfels is shiny while that of Scoria is subvitreous to dull. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Scoria is available in black, brown, dark grey to black, red colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Scoria are as a traction material on snow-covered roads, creating artwork, high-temperature insulation, in gas barbecue grills.