Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
Etymology
From Greek trakhus rough’ or trakhutēs roughness
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,
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Clastic, Splintery
Color
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
Black, Brown, Buff, Green, Grey, Red, Yellow
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Pottery
Types
Not Available
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Jantar Mantar in India
Famous Sculptures
Data Not Available
Data Not Available
Formation
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.
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.
Mineral Content
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Ca, Fe, Mg, Silicon Dioxide, Sodium
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Not Available
Not Available
Porosity
Less Porous
Highly Porous
Cleavage
Not Available
Slaty
Toughness
Not Available
2.6
Specific Gravity
2.7
2.2-2.8
Transparency
Opaque
Opaque
Density
2.43-2.45 g/cm3
2.4-2.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Bangladesh, China, India, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Bulgaria, England, Germany, Norway, Romania, Switzerland
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
South America
Brazil, Chile
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia