Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Discoverer
Unknown
R. J. Hauy
Etymology
From German Grauwacke, from grau grey + wacke
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Clastic
Pegmatitic
Color
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Types
Greywacke
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Archaeological Significance
Formation
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Compound Content
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, 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
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Angular and Fine
Medium to Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Dull
Grainy, Pearly and Vitreous
Specific Gravity
2.2-2.8
2.6-2.63
Transparency
Opaque
Translucent to Opaque
Density
2.6-2.61 g/cm3
2.6-2.65 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Africa
Namibia, Nigeria, South Africa
South Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
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, New Zealand
New South Wales, Queensland, South Australia, Western Australia
Greywacke 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. Greywacke vs Pegmatite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Greywacke and Properties of Pegmatite. Learn more about Greywacke vs Pegmatite in the next section. The interior uses of Greywacke include Decorative aggregates, Floor tiles, Flooring, Homes and Interior decoration whereas the interior uses of Pegmatite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Greywacke and Pegmatite, they have various applications in construction industry. The uses of Greywacke in construction industry include Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate, Raw material for the manufacture of mortar and that of Pegmatite include As dimension stone, Building houses or walls, Construction aggregate, For road aggregate, Landscaping.
More about Greywacke and Pegmatite
Here you can know more about Greywacke and Pegmatite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Greywacke and Pegmatite consists of mineral content and compound content. The mineral content of Greywacke includes Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz 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 Sedimentary Rocks. When we have to compare Greywacke vs Pegmatite, the texture, color and appearance plays an important role in determining the type of rock. Greywacke is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas, Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. Appearance of Greywacke is Dull and that of Pegmatite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Greywacke vs Pegmatite. The hardness of Greywacke is 6-7 and that of Pegmatite is 7. The types of Greywacke are Greywacke 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 Greywacke and Pegmatite is white. The specific heat capacity of Greywacke is 0.71 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.Greywacke is heat resistant, impact resistant, pressure resistant whereas Pegmatite is heat resistant, impact resistant, pressure resistant.