Home

Igneous Rocks + -

Fossil Rocks + -

Metamorphic Rocks + -

Durable Rocks + -

Medium Grained Rocks + -

Compare Rocks


Chert and Skarn


Skarn and Chert


Definition

Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture   
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
Unknown   
USA, Australia   

Discoverer
Unknown   
Tornebohm   

Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use   
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.   

Class
Sedimentary Rocks   
Metamorphic Rocks   

Sub-Class
Durable Rock, Hard Rock   
Durable Rock, Hard Rock   

Family
  
  

Group
Not Applicable   
Not Applicable   

Other Categories
Fine Grained Rock, Opaque Rock   
Fine Grained Rock, Opaque Rock   

Texture

Texture
Banded, Rough   
Earthy, Mud-rich, Rough   

Color
Black, Brown, Green, Grey, Red, White   
Black, Brown, Colourless, Green, Grey, White   

Maintenance
Less   
Less   

Durability
Durable   
Durable   

Water Resistant
Yes   
Yes   

Scratch Resistant
Yes   
Yes   

Stain Resistant
Yes   
No   

Wind Resistant
No   
Yes   

Acid Resistant
Yes   
Yes   

Appearance
Glassy or Pearly   
Dull   

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Homes   
Decorative Aggregates, Entryways, Interior Decoration   

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

Other Architectural Uses
Curbing   
Curbing   

Industry
  
  

Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points   
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
Not Yet Used   
Not Applicable   

Antiquity Uses
Artifacts, Monuments   
Artifacts, Monuments, Sculpture   

Other Uses
  
  

Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms   
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)   

Types

Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter   
Endoskarns   

Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate   
Host Rock for Lead, Zinc and Copper Deposits   

Archaeological Significance
  
  

Monuments
Used   
Used   

Famous Monuments
Data Not Available   
Data Not Available   

Sculpture
Not Yet Used   
Used   

Famous Sculptures
Not Applicable   
Data Not Available   

Pictographs
Not Used   
Not Used   

Petroglyphs
Not Used   
Not Used   

Figurines
Not Yet Used   
Used   

Fossils
Present   
Absent   

Formation

Formation
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.   
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
Quartz, Silicon   
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite   

Compound Content
Silicon Dioxide   
Au, CaO, Carbon Dioxide, Cu, Fe, MgO   

Transformation
  
  

Metamorphism
No   
Yes   

Types of Metamorphism
Not Applicable   
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism   

Weathering
No   
No   

Types of Weathering
Not Applicable   
Not Applicable   

Erosion
Yes   
No   

Types of Erosion
Chemical Erosion   
Not Applicable   

Properties

Physical Properties
  
  

Hardness
6.5-7   
6.5   

Grain Size
Very fine-grained   
Fine Grained   

Fracture
Uneven, Splintery or Conchoidal   
Irregular   

Streak
White   
Light to dark brown   

Porosity
Highly Porous   
Less Porous   

Luster
Waxy and Dull   
Waxy and Dull   

Compressive Strength
450.00 N/mm2   
1
Not Available   

Cleavage
Non-Existent   
Slaty   

Toughness
1.5   
2.4   

Specific Gravity
2.5-2.8   
2.86   

Transparency
Translucent to Opaque   
Opaque   

Density
2.7 g/cm3   
2.8-2.9 g/cm3   

Thermal Properties
  
  

Specific Heat Capacity
0.74 kJ/Kg K   
19
0.92 kJ/Kg K   
10

Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant   
Heat Resistant   

Reserves

Deposits in Eastern Continents
  
  

Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam   
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka   

Africa
Kenya, Morocco, South Africa, Tanzania   
South Africa, Western Africa   

Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom   
United Kingdom   

Others
Greenland, Mid-Atlantic Ridge   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada, Mexico, USA   
Canada   

South America
Bolivia, Brazil   
Brazil, Colombia, Paraguay   

Deposits in Oceania Continent
  
  

Australia
New South Wales, Queensland, South Australia, Western Australia   
Central Australia, Western Australia   

Summary >>
<< Reserves

All about Chert and Skarn Properties

Know all about Chert and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Skarn belongs to Metamorphic Rocks.Texture of Chert is Banded, Rough whereas that of Skarn is Earthy, Mud-rich, Rough. Chert appears Glassy or Pearly and Skarn appears Dull. The luster of Chert and Skarn is waxy and dull. Chert is available in black, brown, green, grey, red, white colors whereas Skarn is available in black, brown, colourless, green, grey, white colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).

Compare Sedimentary Rocks

Fossil Rocks

Fossil Rocks

» More Fossil Rocks

Compare Sedimentary Rocks

» More Compare Sedimentary Rocks