Definition
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Hornblendite is a type of igneous plutonic rock consisting mainly of amphibole hornblende and is a type of Amphibolite rock
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 German, Horn horn + blende
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic, Splintery
Banded, Foliated, Massive
Color
Black, Brown, Buff, Green, Grey, Red, Yellow
Black, Brown, Green, Grey
Durability
Durable
Durable
Appearance
Muddy
Foliated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Antiquity Uses
Artifacts, Sculpture
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Pottery
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Hornblende Gabbro and Hornblende Peridotite
Features
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Archaeological Significance
Famous Monuments
Jantar Mantar in India
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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.
Hornblendite 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.
Mineral Content
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Amphibole, Calcite, Hornblade, Magnetite, Plagioclase, Wollastonite
Compound Content
Ca, Fe, Mg, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Medium to Coarse Grained
Fracture
-
Irregular to Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Luster
Dull
Vitreous to Dull
Specific Gravity
2.2-2.8
2.5
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
2.85-3.07 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
Russia, Turkey
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Germany, Greece, Iceland, Norway, Poland
Deposits in Western Continents
North America
USA
Canada, USA
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
South Australia, Western Australia