Definition
Trachyandesite is an extrusive igneous rock.
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Discoverer
Unknown
R. J. Hauy
Etymology
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Pegmatitic
Color
Black, Brown, Light to Dark Grey
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Layered, Banded, Veined and Shiny
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Artifacts, Sculpture
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Pottery
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Types
Basaltic Trachyandesite
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Archaeological Significance
Formation
Trachyandesite 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.
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Mineral Content
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical 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 Grained
Medium to Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Earthy
Grainy, Pearly and Vitreous
Specific Gravity
2.8-3
2.6-2.63
Transparency
Opaque
Translucent to Opaque
Density
2.9-3.1 g/cm3
2.6-2.65 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Africa
South Africa
South Africa
Europe
Iceland
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
-
New South Wales, Queensland, South Australia, Western Australia
Trachyandesite vs Pegmatite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Trachyandesite vs Pegmatite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Trachyandesite and Properties of Pegmatite. Learn more about Trachyandesite vs Pegmatite in the next section. The interior uses of Trachyandesite include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Pegmatite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Trachyandesite and Pegmatite, they have various applications in construction industry. The uses of Trachyandesite in construction industry include Building houses or walls, Cobblestones, For road aggregate, Rail track ballast, Roadstone and that of Pegmatite include As dimension stone, Building houses or walls, Construction aggregate, For road aggregate, Landscaping.
More about Trachyandesite and Pegmatite
Here you can know more about Trachyandesite and Pegmatite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Trachyandesite and Pegmatite consists of mineral content and compound content. The mineral content of Trachyandesite includes Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase and mineral content of Pegmatite includes Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz. You can also check out the list of all Igneous Rocks. When we have to compare Trachyandesite vs Pegmatite, the texture, color and appearance plays an important role in determining the type of rock. Trachyandesite is available in black, brown, light to dark grey colors whereas, Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. Appearance of Trachyandesite is Dull and Soft and that of Pegmatite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Trachyandesite vs Pegmatite. The hardness of Trachyandesite is 4-5 and that of Pegmatite is 7. The types of Trachyandesite are Basaltic Trachyandesite whereas types of Pegmatite are Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Trachyandesite is light to dark brown while that of Pegmatite is white. The specific heat capacity of Trachyandesite is 0.84 kJ/Kg K and that of Pegmatite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Trachyandesite is heat resistant, pressure resistant, wear resistant whereas Pegmatite is heat resistant, impact resistant, pressure resistant.