Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Discoverer
Unknown
Unknown
Etymology
From German Grauwacke, from grau grey + wacke
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic
Clastic or Non-Clastic
Color
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Grey, White, Yellow
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing, Whetstones
Powder
Construction Industry
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper
Types
Greywacke
Chalk Marl and Marl
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Calcite, Clay, Clay Minerals, Quartz, Sand
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
Ca, NaCl, CaO
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Angular and Fine
Very fine-grained
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.2-2.8
2.3-2.4
Transparency
Opaque
Opaque
Density
2.6-2.61 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Namibia, Nigeria, South Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
England, France, Germany, Spain, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
Greywacke vs Chalk 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 Chalk characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Greywacke and Properties of Chalk. Learn more about Greywacke vs Chalk in the next section. The interior uses of Greywacke include Decorative aggregates, Floor tiles, Flooring, Homes and Interior decoration whereas the interior uses of Chalk include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Greywacke and Chalk, 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 Chalk include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for manufacture of quicklime and slaked lime, Source of calcium.
More about Greywacke and Chalk
Here you can know more about Greywacke and Chalk. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Greywacke and Chalk 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 Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand. You can also check out the list of all Sedimentary Rocks. When we have to compare Greywacke vs Chalk, 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, Chalk is available in grey, white, yellow colors. Appearance of Greywacke is Dull and that of Chalk is Soft. Properties of rock is another aspect for Greywacke vs Chalk. The hardness of Greywacke is 6-7 and that of Chalk is 1. The types of Greywacke are Greywacke whereas types of Chalk are Chalk Marl and Marl. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Greywacke and Chalk is white. The specific heat capacity of Greywacke is 0.71 kJ/Kg K and that of Chalk is 0.90 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 Chalk is heat resistant.