Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Kimberlite is a rare, blue-tinged, coarse-grained intrusive igneous rock, which sometimes contains diamonds and is mostly found in South Africa and Siberia.
History
Origin
-
Kimberley, South Africa
Discoverer
Unknown
John W. Judd
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From Kimberley + -ite, from the name of the South African town of Kimberley where the rock was first found.
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Texture
Banded, Rough
Porphyritic
Color
Black, Brown, Green, Grey, Red, White
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy or Pearly
Dull and Banded
Architecture
Interior Uses
Decorative Aggregates, Homes
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, Paving Stone, Garden Decoration
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, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Basaltic Kimberlites and Micaceous Kimberlites
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
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.
Kimberlite is an igneous rock and is the main source of diamonds. Its formation takes place deep beneath the Earth’s surface between 150 to 450 kilometres, and are erupted rapidly and violently.
Composition
Mineral Content
Quartz, Silicon
Garnet, Olivine, Phlogopite, Pyroxene
Compound Content
Silicon Dioxide
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
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
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6.5-76-7
1
7
👆🏻
Grain Size
Very fine-grained
Fine to Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Streak
White
White
Porosity
Highly Porous
Very Less Porous
Luster
Waxy and Dull
Subvitreous to Dull
Compressive Strength
450.00 N/mm2260.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Conchoidal
Toughness
1.5
-
Specific Gravity
2.5-2.82.86-2.87
0
8.4
👆🏻
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.7 g/cm32.95-2.96 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.74 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Russia
Africa
Kenya, Morocco, South Africa, Tanzania
Angola, Botswana, Cameroon, Ethiopia, South Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
England, Hungary, Iceland, United Kingdom
Others
Greenland, Mid-Atlantic Ridge
Antarctica
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Bolivia, Brazil
Argentina, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, New Zealand, South Australia, Western Australia