Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Discoverer
Unknown
Unknown
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Banded, Foliated, Platy
Color
Grey, White, Yellow
Black, Brown, Pink, Red, White
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Powder
Curbing
Construction Industry
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
As Dimension Stone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
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
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Chalk Marl and Marl
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Famous Monuments
-
Konark Sun Temple in India, Washington Monument, US
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Ca, NaCl, CaO
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Grain Size
Very fine-grained
Medium to Coarse Grained
Porosity
Highly Porous
Very Less Porous
Specific Gravity
2.3-2.4
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
2.49-2.50 g/cm3
2.6-2.9 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
England, France, Germany, Spain, United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Colombia
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New South Wales, New Zealand, Queensland, Victoria
Chalk vs Gneiss 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. Chalk vs Gneiss characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chalk and Properties of Gneiss. Learn more about Chalk vs Gneiss in the next section. The interior uses of Chalk include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Gneiss include Countertops, Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Chalk and Gneiss, they have various applications in construction industry. The uses of Chalk in construction industry 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 and that of Gneiss include As dimension stone.
More about Chalk and Gneiss
Here you can know more about Chalk and Gneiss. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chalk and Gneiss consists of mineral content and compound content. The mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand and mineral content of Gneiss includes Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon. You can also check out the list of all Sedimentary Rocks. When we have to compare Chalk vs Gneiss, the texture, color and appearance plays an important role in determining the type of rock. Chalk is available in grey, white, yellow colors whereas, Gneiss is available in black, brown, pink, red, white colors. Appearance of Chalk is Soft and that of Gneiss is Foliated. Properties of rock is another aspect for Chalk vs Gneiss. The hardness of Chalk is 1 and that of Gneiss is 7. The types of Chalk are Chalk Marl and Marl whereas types of Gneiss are Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chalk and Gneiss is white. The specific heat capacity of Chalk is 0.90 kJ/Kg K and that of Gneiss is 0.70 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chalk is heat resistant whereas Gneiss is heat resistant, pressure resistant, scratch resistant, wear resistant.