Definition
Marl is an unconsolidated sedimentary rock consisting of clay and lime
  
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
  
History
  
  
Origin
Unknown
  
Hawaii Islands
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Old French marle, from Late Latin marglia
  
From Greek pikros bitter + -ite, 19th century
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Earthy
  
Earthy, Rough
  
Color
Beige, Brown, Green, Grey, White
  
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
Yes
  
Appearance
Rough and Dull
  
Rough and Shiny
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Floor Tiles
  
Countertops, Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, Roof Tiles
  
As Building Stone, As Facing Stone, 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
  
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
  
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
  
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
  
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
  
Oceanite
  
Features
Generally rough to touch, Is one of the oldest rock, Splintery, Very fine grained rock
  
Host Rock for Lead
  
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.
  
Picrite 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.
  
Composition
  
  
Mineral Content
Calcite, Clay, Dolomite, Gypsum, Micas, Pyrite, Quartz
  
Biotite, Olivine, Plagioclase, Pyrrhotite
  
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
  
Al, CaO, Carbon Dioxide, Mg, MgO
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
2-3
  
6.8
  
Grain Size
Very fine-grained
  
Fine Grained
  
Fracture
Conchoidal
  
Uneven
  
Streak
White
  
White, Greenish White or Grey
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Subvitreous to Dull
  
Compressive Strength
Not Available
  
189.00 N/mm
2
  
11
Cleavage
Not Available
  
Imperfect
  
Toughness
2.6
  
2.1
  
Specific Gravity
2.2-2.8
  
2.75-2.92
  
Transparency
Opaque
  
Opaque
  
Density
2.4-2.8 g/cm3
  
1.5-2.5 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.88 kJ/Kg K
  
13
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Pakistan, Russia
  
India, Russia
  
Africa
Ethiopia, Kenya, Morocco, South Africa
  
South Africa
  
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
  
Iceland
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
USA
  
Canada, USA
  
South America
Colombia, Ecuador, Peru
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, Victoria, Western Australia
  
Not Yet Found