Definition
Lamprophyre is uncommon igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
History
Origin
-
-
Discoverer
Unknown
Unknown
Etymology
From Greek lampros bright and shining + porphureos purple
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Porphyritic
Banded, Rough
Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Black, Brown, Green, Grey, Red, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Glassy or Pearly
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Other Uses
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Lamprophyre formation takes place deep beneath the Earth’s surface at around 150 to 450 kilometres, and are erupted rapidly and violently.
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.
Composition
Mineral Content
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Quartz, Silicon
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Impact Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Physical Properties
Hardness
5-66.5-7
1
7
👆🏻
Grain Size
Fine to Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Streak
White
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Waxy and Dull
Compressive Strength
120.00 N/mm2450.00 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
-
Toughness
-
1.5
Specific Gravity
2.86-2.872.5-2.8
0
8.4
👆🏻
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.95-2.96 g/cm32.7 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.74 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
England, Hungary, Iceland, United Kingdom
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Antarctica, Greenland
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Mexico, USA
South America
Argentina, Colombia, Ecuador
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, South Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia