Variolite

Skarn

Variolite and Skarn

Variolite

Skarn

Add ⊕

Definition

Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance

Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin

History

Origin

France

USA, Australia

Discoverer

Unknown

Tornebohm

Etymology

From Latin varius, speckled, variegated

From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Earthy, Mud-rich, Rough

Color

Black, Brown, Light to Dark Grey

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Dull

Uses

Architecture

Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

Garden Decoration, Office Buildings

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)

Types

Metamorphic rock

Endoskarns

Features

Has High structural resistance against erosion and climate, Very fine grained rock

Host Rock for Lead, Zinc and Copper Deposits

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.

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

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite

Compound Content

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

Au, CaO, Carbon Dioxide, Cu, Fe, MgO

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

Properties

Physical Properties

Hardness

66.5

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Irregular

Streak

White to Grey

Light to dark brown

Porosity

Less Porous

Luster

Waxy and Dull

Compressive Strength

37.50 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.3

2.4

Specific Gravity

2.8-32.86

0 8.4

👆🏻

Transparency

Opaque

Density

2.9-3.1 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

China, India, Russia, Saudi Arabia, South Korea, Sri Lanka

Africa

South Africa

South Africa, Western Africa

Europe

Iceland

United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

Canada

South America

Brazil

Brazil, Colombia, Paraguay

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

All about Variolite and Skarn Properties

Know all about Variolite and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Variolite belongs to Igneous Rocks while Skarn belongs to Metamorphic Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Skarn is Earthy, Mud-rich, Rough. Variolite appears Dull and Soft and Skarn appears Dull. The luster of Variolite is while that of Skarn is waxy and dull. Variolite is available in black, brown, light to dark grey colors whereas Skarn is available in black, brown, green, grey, white colors. The commercial uses of Variolite are cemetery markers, creating artwork and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).