Definition
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Discoverer
Edgar Bailey
Alexandre Brongniart and René Just Haüy
Etymology
From French schiste, Greek skhistos i.e. split
From Greek trakhus rough’ or trakhutēs roughness
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Aphanitic to Porphyritic
Color
Blue, Bluish - Grey, Purple, Shades of Blue
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
Durability
Durable
Durable
Appearance
Dull and Banded
Banded
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Not Yet Used
Curbing
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Cemetery Markers, Creating Artwork
Types
Not Available
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Formation
Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.
Mineral Content
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Not Applicable
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Not Available
Streak
White to Grey
White
Porosity
Highly Porous
Less Porous
Compressive Strength
Not Available
Cleavage
Slaty
Not Available
Toughness
1.5
Not Available
Specific Gravity
3-3.2
2.7
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.43-2.45 g/cm3
Resistance
Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Japan, Turkey
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Egypt, Ethiopia, South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
France, Greece, Iceland
Bulgaria, England, Germany, Norway, Romania, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
South America
Not Yet Found
Brazil, Chile
Deposits in Oceania Continent
Australia
New Zealand
New Zealand, Queensland, South Australia, Western Australia