Definition
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Discoverer
Unknown
Unknown
Etymology
From Latin term that means purple
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Clastic or Non-Clastic
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Grey, White, Yellow
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
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
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
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
Not Available
Not Available
Features
Host Rock for Lead
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Formation
Rhomb-porphyry 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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Alkali feldspar, Biotite, Plagioclase, Pyroxene
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
CaO, Cl, MgO
Ca, NaCl, CaO
Types of Metamorphism
Impact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Not Available
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
Not Available
Cleavage
Perfect
Non-Existent
Specific Gravity
2.86
2.3-2.4
Transparency
Translucent
Opaque
Density
2.8-2.9 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Not Yet Found
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Bulgaria
England, France, Germany, Spain, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
Rhomb Porphyry 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. Rhomb Porphyry vs Chalk characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rhomb Porphyry and Properties of Chalk. Learn more about Rhomb Porphyry vs Chalk in the next section. The interior uses of Rhomb Porphyry include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Chalk include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Rhomb Porphyry and Chalk, they have various applications in construction industry. The uses of Rhomb Porphyry in construction industry include As a flux in the production of steel and pig iron, As a sintering agent in steel industry to process iron ore, As dimension stone, Cement manufacture, For road aggregate, Making natural cement, Manufacture of magnesium and dolomite refractories 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 Rhomb Porphyry and Chalk
Here you can know more about Rhomb Porphyry and Chalk. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rhomb Porphyry and Chalk consists of mineral content and compound content. The mineral content of Rhomb Porphyry includes Alkali feldspar, Biotite, Plagioclase, Pyroxene and mineral content of Chalk includes Calcite, Clay, Clay Minerals, Quartz, Sand. You can also check out the list of all Igneous Rocks. When we have to compare Rhomb Porphyry vs Chalk, the texture, color and appearance plays an important role in determining the type of rock. Rhomb Porphyry is available in black, brown, colourless, green, grey, pink, white colors whereas, Chalk is available in grey, white, yellow colors. Appearance of Rhomb Porphyry is Rough and that of Chalk is Soft. Properties of rock is another aspect for Rhomb Porphyry vs Chalk. The hardness of Rhomb Porphyry is 5-5.5 and that of Chalk is 1. The types of Rhomb Porphyry are Not Available whereas types of Chalk are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rhomb Porphyry and Chalk is white. The specific heat capacity of Rhomb Porphyry is 0.92 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.Rhomb Porphyry is heat resistant, pressure resistant whereas Chalk is heat resistant.