Definition
Marl is an unconsolidated sedimentary rock consisting of clay and lime
  
Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix
  
History
  
  
Origin
Unknown
  
Egypt
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Old French marle, from Late Latin marglia
  
From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Earthy
  
Porphyritic
  
Color
Beige, Brown, Green, Grey, White
  
Black, Brown, Colourless, Green, Grey, Red, Rust, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Rough and Dull
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
As Building Stone, Roof Tiles
  
Garden Decoration, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
  
Construction Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Jewellery, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Soil Conditioner
  
Creating Artwork, Gemstone, Jewelry
  
Types
Clay Marl ,Blue Marl, Red Marl, High Bank Marl, Shell Layer Marl, Under Shell Layer Marl, Sand Marl, Green Marl, Grey Marl and Clayey Marl
  
Rhomb Porphyry
  
Features
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
  
Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
Formation
Marl forms when very fine-grained clay particles are deposited in water which settles at the bottom of water bodies and are compacted by overlying sediment; the water squeezes out and hence forming Marl rock.
  
Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.
  
Composition
  
  
Mineral Content
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
  
Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica
  
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering, Chemical Weathering, Not Registered
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
2-3
  
6-7
  
Grain Size
Very fine-grained
  
Fine Grained
  
Fracture
Conchoidal
  
Irregular
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Dull
  
Cleavage
Not Available
  
Imperfect
  
Toughness
2.6
  
1.7
  
Specific Gravity
2.2-2.8
  
2.5-4
  
Transparency
Opaque
  
Translucent to Opaque
  
Density
2.4-2.8 g/cm3
  
2.5-2.52 g/cm3
  
Thermal Properties
  
  
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Pakistan, Russia
  
China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam
  
Africa
Ethiopia, Kenya, Morocco, South Africa
  
Egypt, Ethiopia, Ghana, South Africa
  
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
  
Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
USA
  
Canada, Cuba, Jamaica, USA
  
South America
Colombia, Ecuador, Peru
  
Bolivia, Brazil, Colombia, Ecuador, Paraguay
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, Victoria, Western Australia
  
New South Wales, New Zealand, Western Australia