Definition
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
History
Origin
-
-
Discoverer
Johann Gottlob Lehmann
Unknown
Etymology
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
From the mineral feldspathoid which is the main content of rock
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic, Splintery
Earthy
Color
Black, Brown, Buff, Green, Grey, Red, Yellow
Black, Brown, Green, Grey, Pink, White
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Muddy
Dull
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Cement Manufacture, for Road Aggregate
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Creating Artwork, Pottery
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Igneous rock
Features
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
Jantar Mantar in India
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
Foidolites is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Composition
Mineral Content
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Compound Content
Ca, Fe, Mg, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
-
Physical Properties
Hardness
31.5
1
7
👆🏻
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
-
Conchoidal
Streak
White
White
Porosity
Highly Porous
Very Less Porous
Luster
Dull
Subvitreous to Dull
Compressive Strength
95.00 N/mm280.00 N/mm2
0.15
450
👆🏻
Cleavage
Slaty
Perfect
Toughness
2.6
-
Specific Gravity
2.2-2.82.86
0
8.4
👆🏻
Transparency
Opaque
Translucent
Density
2.4-2.8 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.39 kJ/Kg K0.79 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
Russia
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
South Africa, Western Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
-
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
-
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Central Australia, Western Australia