Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
History
Origin
-
-
Discoverer
Alexandre Brongniart and René Just Haüy
Unknown
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From the mineral feldspathoid which is the main content of rock
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy
Color
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
Black, Brown, Green, Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded
Dull
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
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
As Dimension Stone, Cement Manufacture, for Road Aggregate
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Felsic volcanic rock
Igneous rock
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Host Rock for Lead
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
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
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Compound Content
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional 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, Sea Erosion, Water Erosion, Wind Erosion
-
Physical Properties
Hardness
61.5
1
7
👆🏻
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
-
Conchoidal
Streak
White
White
Porosity
Less Porous
Very Less Porous
Luster
Metallic
Subvitreous to Dull
Compressive Strength
150.00 N/mm280.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Perfect
Toughness
-
-
Specific Gravity
2.72.86
0
8.4
👆🏻
Transparency
Opaque
Translucent
Density
2.43-2.45 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.79 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
South Africa, Western Africa
Europe
Bulgaria, England, Germany, Norway, Romania, Switzerland
-
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil, Chile
-
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Western Australia
Central Australia, Western Australia