Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
  
Vogesite is a porphyritic alkaline igneous rock and is a variety of Lamprophyre which is dominated by essential amphibole, usually hornblende, and potassic feldspar
  
History
  
  
Discoverer
Unknown
  
Unknown
  
Etymology
From French schiste, Greek skhistos i.e. split
  
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
  
Texture
Foliated, Platy
  
Porphyritic
  
Color
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
  
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Layered and Shiny
  
Dull, Banded and Foilated
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles, Interior Decoration
  
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
  
Exterior Uses
Garden Decoration, Paving Stone
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Not Yet Used
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
  
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
  
Medical Industry
Not Yet Used
  
Taken as a Supplement for Calcium or Magnesium
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Used in aquariums, Writing Slates
  
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
  
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
  
Features
Easily splits into thin plates, Smooth to touch
  
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
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
  
Vogesite formation takes place deep beneath the Earth’s surface at around 150 to 450 kilometres, and are erupted rapidly and violently.
  
Composition
  
  
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
  
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
  
Compound Content
CaO, Carbon Dioxide, MgO
  
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
3.5-4
  
5-6
  
Grain Size
Medium to Fine Coarse Grained
  
Fine to Coarse Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Shiny
  
Subvitreous to Dull
  
Cleavage
Slaty
  
Conchoidal
  
Toughness
1.5
  
Not Available
  
Specific Gravity
2.5-2.9
  
2.86-2.87
  
Transparency
Opaque
  
Translucent to Opaque
  
Density
2.8-2.9 g/cm3
  
2.95-2.96 g/cm3
  
Thermal Properties
  
  
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
  
Russia
  
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
  
Angola, Botswana, Cameroon, Ethiopia, South Africa
  
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
  
England, Hungary, Iceland, United Kingdom
  
Others
Not Yet Found
  
Antarctica, Greenland
  
Deposits in Western Continents
  
  
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
  
Canada, Mexico, USA
  
South America
Brazil, Colombia, Guyana
  
Argentina, Colombia, Ecuador
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Queensland
  
New South Wales, New Zealand, Queensland, South Australia, Western Australia